First, I was concerned about the location: our existing Samsung 32″ TV is mounted onto the framed backside of the pantry by the dining room table. I didn’t think I was going to be able to put it behind the TV, and if it had to go inside the pantry the remote wouldn’t work. Both points were met (it was small but not small enough – it went inside the pantry).
Pro – small size
Pro – can use your existing TV remote
Pro – includes HDMI cable

Second, my PC didn’t immediately see it, I messed around with router/network/firewall settings before I just recycled the MediaLive, then everything worked perfectly (I have Windows 7, so a little uncertainty there).
Pro – works with Windows 7
Pro – didn’t have to change any firewall/router/network settings after all

Finally, it came up and recognized that there was an update available, so immediately updated and came back online. I use a wired connection, no complaints about the speed or connectivity. I saw and played my recorded TV, but didn’t see any movies. Also, some of the menu items were missing (this is my first Extender). Didn’t know that NetFlix was NOT available for the MediaLive. It didn’t see my Amazon Unbox videos immediately. I had to point it to my folder where the videos were stored before it would see them, and viola – they played perfectly!
Pro – updates itself automatically
Con – doesn’t automatically see your Video libraries
Con – NetFlix not included (I don’t use NetFlix anyways, so no loss for me)
Pro – does play Amazon UnBox

I’m not so concerned about the startup and shutdown time – it wasn’t that bad, nothing to complain about. Also, as I don’t have HD cable on my PC, I haven’t recorded in HD so far. I’m not sure about NetFlix and UnBox HD offerings either…

Overall, great little box if you have a Samsung TV (2008 or newer)!