Welcome!
I agree with my fellow members - SeatGuru, to name names, has slid down a very slippery slope , particularly since being taken over by Trip Advisor (I believe they don't really know what to do with it). Their graphics are OK, but their information is often significantly out of date and remains so even when people communicate corrective information to them.
SeatExpert's renderings (graphics) seem a bit less crisp, but they do work, there is more information generally in the text and I like the smart move of hooking up with TripIt for "seat recommendations" - nice move!
(Soon it will be time to load the new AA777-300ER... and the 777-200ER will be losing First, and 777 as well. 767-300ER and others will be / are already adding Main Cabin Extra (e.g. 763 goes from a minicabin with four rows of usual coach to three rows of MCE. Good luck keeping up - but as infamousdx, putting all of us passengers to work will make it easier, IMO.)