This is the second Retron system I've purchased. The first one I bought was a gift for my parents; it was the one that only plays NES games, but same brand as this one. Other reviews of the Retron systems have said that these don't last... the one I bought for my parents is still alive and kickin' after 2 years with almost daily use.

That said, after spending Thanksgiving with my parents and having a blast playing the old NES games on their system, I decided I wanted my own.

Here is what I like about the twin model:
*Convenience. Two types of games can play on one machine! Saves room and a lot less wires versus having two separate systems. Can switch back and forth between NES and SNES with just the flip of a button.
*Easy to hook up
*YAY!! I CAN PLAY MY OLD NINTENDO GAMES!!!

Here are some things you should know before buying:

*It is light. I mean, alarmingly light to where you aren't sure that there is anything in the box. Very thin plastic and sounds pretty much hollow if you tap it. Don't know how well it would hold up if you had kids around who would be rough with it, or if you're a clumsy drunk.
*Just like with the first Retron I bought, the controllers are junk. Very flimsy and really short cords. BUT the system is compatible with the original NES and SNES controllers... so dig out your old ones or buy the originals here on Amazon or ebay. They go for about $5-$10 used.
*It has a major death grip on the SNES cartridges. It is a little scary to pull them out. I worry that I will break something, either the Retron or the cartridge. Be careful.

If you buy it, I advise cleaning your old games as thoroughly as you can before using them, just for the sake of not getting any dust or grime in your new system. I've found that I've put certain games in the system that I thought were fairly clean, but they didn't play. Just take a q-tip and wipe the connection really well. System seems really sensitive to dirt. There are oodles of how-to articles and videos on the internet for a more thorough game cleaning. There are also fancy cleaning kits you can buy online.

Maybe it's overkill, but I also have a pillowcase that I slip the system into when we're not using it, just because we have a lot of animals, and pet hair and dust seem to get in everything. This has kept my system very clean.

Of course nothing will ever measure up to the original Nintendo consoles... but this is a close second. Despite the few drawbacks I mentioned, I still have a lot of fun with it!
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UPDATE 6/28/14
It has been a very happy two years with my Retron. It still works like a champ. Considering the cheap plastic quality of the machine, a two year life span is pretty incredible. I wish I could tell you exactly how long the Retron lives, but I sold it recently to a nice fellow on Craigslist. I just bought a Wii U. With many of the old NES and SNES games availible for download, it seemed pointless to keep my Retron hanging around.
My parents' Retron (the NES model) is still alive and well after nearly 4 years. They are much harder on their machine-- it is very dusty and full of cat hair, but it still works. So I guess that cheap, hollow plastic quality is actually much better than it looks.

I bought this for my nephew who is 12 but is an absolute game lover. He specifically asked for this on his christmas list. As someone who grew up with the original NES ans Snes I was more than happy to buy this for him. We first hooked it up on an LED TV with the AV cords. I gave him the original Zelda and Super Mario for NES and Super Mario Kart and Ultimate Mortal Kombat for SNES. The NES games worked fine but the video quality was off. Both of the SNES games had problems. Mario Kart would not stop rolling on the screen and Mortal Kombat would not go beyond black. Once we moved the system into another room onto an older, NON FLAT SCREEN, BIG ASS HEAVY GLASS FRONT TV, everything worked perfectly. Video quality was perfect and all of the games so far have worked great. Oh and by the way if you want to play Duck Hunt or any other game with the Gun you have to have a glass front TV. Most People have the TVs to work with this but if you don't you can always go to goodwill or a pawn shop and buy one cheap. They work great with the TVs they were built for. This is the only one that can connect two NES and two SNES controllers. All of the other ones only take one of each. This is the one to buy.

First of all, yes, most NES and SNES games work. However, I've had problems with non-official NES games such as Tengen carts not working. Gauntlet in particular glitches out.

I was worried about the sound being different because this is emulation, but I can't tell a difference in the sound from the original SNES. The picture is a bit blurry at times, but that's probably mainly due to me using this on a modern TV, not a CRT. For some reason none of the menus have sound either, or just buzz. Not a deal breaker, but annoying.

There is one huge annoying flaw though. Taking games out is overly difficult. There is no NES eject button which is ridiculous, and sometimes the SNES eject won't work either. And the console has a very hard grip on all cartridges, it takes a lot of physical effort to pull them out. I doubt a child would have the hand strength be able to take the games out without damaging the game or console.

Another problem is the NES games sometimes have trouble reading. It usually takes multiple attempts reinserting and removing NES games to get them to work NES games will wobble because while they fit firmly at the bottom, there's not enough support to hold up the top section of the cartridges. This can cause a couple problems. Sometimes it takes multiple attempts putting cartridges in and taking them out to get them to work, you have to insert them just right. Which wouldn't be such a big issue if the console didn't grip the cartridges so firmly at the base. Because of the lack of support for the top sections of the cartridges, if you move the console slightly while it's being used it can cause the game to freeze, and you'll have to restart the console and you'll lose all your progress in your game. But just get a controller with a cord that has plenty of length and it won't be a problem.

Also the console is not sturdy, the plastic is flimsy. The SNES to NES button is very fragile.

Other flaw is for some dumb reason the controller ports are on the side of the console, not the front.

The controllers that come with the console are terrible as expected. Mainly due to the very short cords. They're only 3 feet long or so, you have to be right in front of your TV to use them. The controllers works ok, but I find the dpad to be cheap and not read inputs all that well. They're ok to keep as a backup, but you'll want to invest in a name brand nintendo controller for sure. Luckily all NES and SNES controllers are compatible.

Lastly, my other complaint is shipping took quite a while. Almost 2 full weeks.

Overall, I'd recommend you buy because the price is cheap ($45). It's a fair deal for what you get. Just don't expect to have your mind blown.

EDIT: The problems I had and continue to have with the NES games made me bring my rating down to 2 stars. Lack of support for the cartridges made it very difficult for NES games to work on this thing, and finally after a few months of regular use the thing finally broke. One of the metal pieces came out while I was removing a cartridge, probably due to the uneccessary death grip this thing has on carts. I'm going to keep this around for playing SNES games but I'm just going to pick up a good condition real NES for my NES titles. Playing NES games on this thing was such a nightmare, I'm almost glad the thing broke.