GOD uses
GAIM on both my desktop (Linux/XP dual boot), and a Linux laptop ...
I have TONS of contacts over ICQ/YAHOO/MSN/AIM/GTALK and I have no issues at all ...
I used Trillian for many years, but eventually looked for a replacement due to v3.x repeatedly 'orphaning' contancts, and Crulean seemed not to be in a hurry to fix it ...
Remember: no matter which IM software you use, if you save histories, once in a while they do need to be purged/deleted ...