Im doing research on which one of these to use and I can\'t really find one that stands out. Eaccelerator is faster than APC, but APC is better maintained. Xcache is faster
In the end I went with eAccelerator - the speed boost, the smaller memory footprint and the fact that is was very easy to install swayed me. It also has a nice web-based front end to clear the cache and provide some stats.
The fact that its not maintained anymore is not an issue for me - it works, and that's all I care about. In the future, if it breaks PHP6 (or whatever), then I'll re-evaluate my decision and probably go with APC simply because its been adopted by the PHP developers (so should be even easier to install)