Pros: Small (plugs directly into TV's HDMI port), can be powered via TV's USB port (which eliminates yet another power cord to plug in) Con: Remote conflicted with other signals and required excessive work-arounds. Wound up using iTouch and Roku app to control it, and even then, it isn't always responsive. Effect is to get stuck on a channel or to have to unplug/restart Roku. On balance, my old, no-longer-supported Roku XD was more reliable, although the software lacked some of the handy features of current Rokus.
I have an Apple TV, a Roku 2, and the Roku Streaming Stick in my house and the Streaming Stick is hands down the worst streaming device I own. It's slow and "laggy", it often has trouble connecting to the internet, and the remote often loses connection with the streaming stick for some reason and then I have to go through this whole ridiculous ritual of removing the batteries and pushing a bunch of buttons on both the Streaming Stick and remote to try to reconnect the remote. My Apple TV is on its last leg and will be replaced with the new one when it comes out. The Streaming stick will likely find its new home in the bottom of a trash can and be replaced with my old Apple TV.
I have been using Roku for two years and decided to upgrade to the "stick". I does a lot of "loading" and quit working after two weeks. Just dead in the water and wouldn't respond. So, I'm back using the old one and it works just fine.