ideally, it would be really nice if cscope/xcscope provided some means of creating (and saving) bunch of call-stacks, which you can navigate in forwards/reverse direction (not sure if i am making much sense here...)
Also, I've had a lot of luck with pycscope.py for python code + cscope tools.
GNU Global needs some love though. It'd be awesome to see it handle more stuff.
It worked well for my own usage, but it probably needs some love. I'm not sure how *cscope works though, and if it would be possible to add it as another backend.
What's the advantage to acscope vs. the others? I personally use xcscope, I don't even remember why I initially chose it...
ascope is an improvement over xcscope that runs all queries through a single cscope process, instead of starting a new process and reloading the database for each query. It was made by Staton Sun as a merge between xscope and another single-process interface, bscope