I bought one at Best Buy yesterday and set it up.
If I can solve ONE problem, it stays, otherwise I think I'll be returning it.
The Roku doesn't seem to play nice with others. The remote appears to be some form of Bluetooth (it pairs with the box). Ok, no problem. But the remote has NO IDEA that I have a television with it's own features, that I might want to switch from the Roku to my Joey, etc. At least the Dish remote knows it will be used with an IR-based piece of equipment and I can say "Hey, my TV is an Insignia - use their codes for volume control".
Because of this, I can't even buy a learning remote to combine all three devices (TV, Joey, Roku) because the Roku is some form of RF.
That being said, the box itself is wonderful. Set up was fast, though I didn't like having to constantly go back to a computer to enter in codes at various websites to activate/link Netflix, Amazon Prime and MLB.TV. The Plex media client was FANTASTIC in that it automatically found the server and allowed me to choose a higher bitrate since I was using wired ethernet (although the path was a bit convoluted - Roku plugged into a Homelink, through the electrical wires to the router, out some Cat 6 to the hub in the basements and another Cat 6 hop to the actual Windows 8-based machine with the Storage Spaces array on it).
PQ is pretty damn good. I have 35Mbps fiber to my house and got good pictures from both Netflix and Amazon Prime. MLB.TV looked a bit strange in that it would be fuzzy-ish for a moment and THEN give me a nice, crystal clear HD picture (they must use a different buffering scheme but, then again, I *was* trying to watch live stuff on MLB.TV versus pre-recorded on Netflix and Amazon).
I'll be looking for a solution to my "remote trouble".
The ROKU 3 does have an IR sensor. I use my Harmony remote with the ROKU 3 with no issue.
The ROKU uses a progressive buffering scheme. Instead of making you wait for the program to start, it starts your show as soon as possible at a lower bit rate and then as the program buffers the PQ gradually starts to improve. This was true on the last gen ROKU's as well.