Well, 2.4.2 does not work well with gtk2, 2.5.3 on the other hand, is ok with gtk2. I heard that gtk2 uses less cpu. And besides that, 2.5.3 is a lot more bug fixed than 2.4.2, so there may be a lot of reasons why 2.5.3 is more responsive. I personally use aMule with wx-cvs + gtk2, and I have no problems so far. My compilation flags for wxWidgets are:
1) For non-unicode:
./configure --enable-debug --disable-optimise --enable-debug_flag --enable-debug_info --enable-debug_gdb --enable-gtk2 --disable-unicode --prefix=/usr/local/wxWidgets-cvs
2) For unicode:
./configure --enable-debug --disable-optimise --enable-debug_flag --enable-debug_info --enable-debug_gdb --enable-gtk2 --enable-unicode --prefix=/usr/local/wxWidgets-cvsu
My aMule compilation flags are:
./configure --enable-debug --disable-optimize --enable-verbose --enable-webserver --enable-webservergui --enable-amulecmd --enable-amulecmdgui --enable-ccache --with-wx-config=/usr/local/wxWidgets-cvs/bin/wx-config
(of course, you dont need all of these flags, i do that cos I have to test all these programs)
I run aMule like this (non-unicode):
LD_LIBRARY_PATH=/usr/local/wxWidgets-cvs/lib/ verb-cvs/src/amule &
or this (unicode):
LD_LIBRARY_PATH=/usr/local/wxWidgets-cvsu/lib/ verb-cvsu/src/amule &
Hope that helps in case you want to compile all yourself. Cheers!