I use it as I've been weeding out bugs in jimtcl

I start by setting a breakpoint at the segfault or panic, see what value is messed up, set a watchpoint, and run it backwards until I hit that watchpoint. Then it's a matter of alternating forwards and backwards until I find the exact spot

For example, it's kinda amazing to do watch -l someObj->refCount, use rc to run backwards, and find exactly where the refCount was last set