For me it looks "almost" similar. I'm VERY pleased with AES 2.20
Apart for how much you rate "almost" regarding how it looks, and of course looks is of course subjective, fact is that GSX works for free on all our airports, so you'll likely use GSX there in any case since it's replacing the previous ParkMe functions and it will become an integral part of our sceneries, but it also works everywhere else, even in airports of developers that *oppose* to AES (like Blueprint, for example), with a single purchase.
Of course, that's relevant only if you use FSX. With FS9, it's fairly obvious there's no other choice than AES.