Memory size tactics aside, trillian still performs, handles, and generally is more responsive on my system. So, as I said in the IRC channel, I dont care what methods a program uses to lower its memory usage, the fact that it uses little RAM, paging lesser used routines and data to disk, is still a big plus to me. Trillian is very responsive, doesnt require a lot of configuration to get things running in a method which is pleasing and easy to use, and runs very fast on my system. Yes, the startup might take a couple of seconds more, however, as I've said in this thread, I dont look at this as a negative being that I have to restart miranda several times a day due to crashes so totalling up the startup time of the crash experiences to the startup time of trillian puts miranda at a big disadvantage.
But anyways, to each their own. If you want something that just works, and supports more of the features of the official clients, then trillian is better for you. If you want a very minimalistic approach, with gobs of configuration options, then choose miranda.