Yes... you can stream video, music and photos from a computer through the Roku onto the HDTV. You need to add the "Plex" channel from the channel store AND install "Plex Media Server (PMS) on your computer to play on the Plex channel. PMS is free and you can download it from this site: https://plex.tv/downloads
TiVo is a DVR (PVR) for your cable, satellite or antenna. (TV guide, pause/rewind live TV, schedule recordings of TV series, etc.) There is limited support for TiVo in Canada, but I use it (the TiVo Premiere XL) with my antenna where it works great. TiVo has a few other services like Netflix, Amazon Video, HuluPlus and Youtube. It has a unified search, allowing you to search across all your services. It also makes suggestions across all services based on what you watch and how you rate them.
Roku will not connect with your linear TV services, it only connects to the internet, apart from that it gives you the same services as a TiVo as well as vast array of other services. NHL, MLB, Crackle, Facebook and much more. As with the TiVo, the paid services have great video and audio quality (of course, dependent on your internet speed). Roku also has a unified search.
If your TV service allows you to connect it to a TiVo then I wound not hesitate to recommend it. Otherwise use a Roku or an Apple TV, etc. They have more choices (especially the Roku), are less expensive and have no subscription fee. TiVo services cost $15/month.
Mine too started draining very quickly, after I left the headphones plugged in. I did some testing and with the headphones plugged in it draws 60mA which will flatten the battery in a couple of days. No headphones it draws about 1000 times LESS, suggesting more like a year before the batteries are flat. (exact figures will depend in the type of battery used). So the lesson is : unplug the headphones when not in use!
Roku2 supports Standard Definition (older analog tv) and HDTV.....The Roku3 is for HDTV only....Roku2 is wireless only...Roku3 is wireless and Ethernet connectable... Roku3 wireless is dual band (2.4Gz, 5Gz) 802.11a/b/g/n. The Roku3 has a much faster processor for improved casual gaming and channel loadup. The Roku3 is the only model that has the "YouTube" channel whereas the other models do not.
Netflix is installed by default, but when you launch it for the first time on the Roku box you will need to enter your Netflix account info. Roku also has a smart phone app, so you can use that vise your remote. You'll be able to use your smart phone keyboard that way too.
The Roku does not have local TV stations available... All channels are On-Demand(watch when you want to). You can get local TV stations by installing a HD TV Antenna to get FREE OTA(over-the-air) programming in HD. check out the following to see what TV stations are available by your home address: www.antennaweb.org
Short answer is yes, with some limitations.
Here's the Roku blog article on traveling abroad:
And here's an article on getting US content overseas:
Hope this helps