David
Not sure how up to date the wiki is but a few things I've experienced with my TV-
Apart from it working as a TV - full HD, the look, size etc that you want, there are a couple of things to consider
1. Inputs - you need to think about what devices you're planning to connect and how. Ideally, IMHO, everything streams via the MD so all you need is one HDMI input direct from MD or from your AV Receiver, but it can be useful to have the others while you're getting going and/or as backup if your system is down for maintenance or whatever.
2. Control - this is probably the biggie. Even if everything comes via the MD/AV Receiver you will at least want to turn the thing on and off and possibly switch sources and you'd rather that all happened from LinuxMCE rather than you having to pick up the dedicated remote just to do that. You may also require volume and some other commands. Options are RS232, IR, Network (LAN), HDMI CEC. You need to see what the models you're looking at support and find out how easy it is to use those protocols. IR is the most common but can be a bit tricky. LAN and CEC are very new and rather proprietory and will take a fair bit of hacking. RS232 I gather is very reliable but getting rare. If you go IR, it helps if discrete codes are available for things like power (on/of) and input switching (discrete codes for each different source rather than a toggle button).
It helps to design your setup in diagrams and drawing apps with all the connections shown etc so you don't miss things and can ask questions.
I'm still very new at this but hopefully this gives you some food for thought.
