Since Luke has been very good about getting my wish items into slime, here, I think, is the last one that really prevents me from switching completely to slime from ilisp.
In ilisp, if you're in the debugger, pressing C-d pops one level of the debugger. In slime, I press C-d all the time, but cmucl sees a literal C-d and thinks end-of-file. Fortunately, cmucl doesn't exit.
And, since we're wishing right now, here's another feature from ilisp that I like and use once in a while. Comes in handy when you're testing different versions of cmucl, or comparing how different lisps behave.
Ilisp allows several buffers running at the same time. Each buffer is running a different lisp instance. This can be the same lisp or a different lisp implementation altogether.
Anyway, slime rocks!
Ray