I researched treadmills the best I could, but found the available online information to be more generic or more suspicious than, say, car reviews.
Nevertheless, I did trust them enough to narrow down the range about three manufacturers/models. The Sole F80, the Nordic Track C1750, and Smooth 7.35R. [NOTE the 7.35R replaces the 7.35, the console is different, and it has true 15 percent incline.]
Prior to the review proper, just a quick note about the competitor's models that I tried:
I was able find a Nordic Track C1500 (previous model to the 1750) and a Sole F80 at Sears, and tried them out first. I was disheartened to find that I could only try a Smooth by actually ordering one.
While the Nordic Track was impressively better on features and specs, and worked great, it also had the highest deck (probably necessary for negative incline feature) which was for me a negative. Another big negative is that once released from the folding position, it had no slow soft descent (you have to hang on and lower it carefully).
The Sole F80 was also very good, and very easy (too easy?) to move once folded up. But when looking for independent reviews, videos, etc., I encountered so much self-promotional material it crowded out nearly everything else. Amazingly, I decided to buy the Smooth sight unseen, based on the scant reviews, and the longer (7 year) warranty. I also believed that, based on proximity, I could get parts faster, should I need them in the future.
OK. The review: I have only just assembled and used this unit. I can't attest to its durability yet, only the assembly, feel, and user experience.
Don't do curbside delivery. Get this unit delivered to exactly where you want it, right side up, with the front, heavy end (marked on the box) in the right place. Don't plan on moving it much. Unlike some others' reported experience, my box--ordered direct from Smooth--was in pristine condition when I received it two weeks later.
This unit is really easy to assemble with a friend, as there are very few parts that are not preassembled.
The soft release feature is amazing and impressively slow and soft. More so than the Sole, which is also quite adequate.
This unit is very hard to move, or even figure out how to move (instructions notwithstanding) at least on my relatively thin carpet,or figure out how to move. (I am a strong large male, BTW.) Night and day difference from the Sole which is hard not to move once it is in the upright position.
I think the Smooth is the most aesthetically pleasing of the three treadmills I have tried, and it is quiet enough.
I weigh 235 lbs, and have run it so far up to 8mph. It was very solid and stable (and I'm out of breath).
The fan, when activated, is amazingly loud for a tiny little computer type fan. It has two settings, loud and louder. It actually does create a bit of breeze, so I wonder if in response to prior criticism on the weak fan maybe the company tweaked the speed to get better output at the expense of noisier operation. It has a fixed blowing angle however.
The console is pretty primitive. As another review noted, it only shows tenths of miles. I believe the lap feature counts quarter miles. There is support for five users, which AFAIK is only useful for computing calories burned (you enter each user's height/weight/gender). That was just right for us, since we have a family of five. There is the ability to enter two custom programs (I believe two each, for each of the five users), but the process of entering the program is just way too tedious, and makes no allowance to go back to correct anything without having to start over.
The biggest drawback for me compared to the Sole are the available quick settings for speeds and inclines. The 7.35R has a key each for 4/6/8/10 mph. No quick access to anything slower. The inclines go from 2/4/6/8 percent. No easy access to 15%. (BTW, unlike the predecessor 7.35, the 7.35R goes up to full 15 percent grade, not "levels", though their website is still not up to date on this point).
The membrane keys are easier to keep clean, but harder to press than the Sole (there is no tactile feedback). But I wonder if the Sole buttons wouldn't eventually break. The Sole has speed/incline increment/decrement keys on the handles which are easier to use than poking the plus/minus icons directly on the console.
All current treadmills have a safety feature, where you are tethered to a "key" so if you slip too far back, or trip, the unit will come to a halt. The annoying thing--at least on this unit (I didn't check this out on others)--is that there is no way to resume your program in progress even after plugging the key back in. That can only be accomplished with the pause button provided the key stays in place. This could tempt some users to defeat an otherwise terrific safety feature.
I would say the Smooth console has a higher quality feel than the Sole. It is definitely "Smoother" overall. The entire top assembly (console and arms) are plastic, but very tough plastic.
Had I been able to judge the Sole F80 and Smooth 7.35R side-by-side, I probably would have purchased the Sole F80 for ease of movement, and easy to use buttons and adequate 5 year warranty, but I'd feel bad about its cheesier console construction. But then again, nobody walks or runs on the console.