About Boehm GC, somebody told me a story about using it at his job for a highly technical simulation program that they sell... it worked unless the customer had data that fooled the GC into thinking it was seeing pointers in data that wasn't pointers, so it never freed memory. I guess it was in 32 bits with much smaller address space. They ended up switching to manual memory management, which wasn't significantly more complicated (in C++).

Such are the tradeoffs with a conservative garbage collector.

I would avoid Boehm GC (and other conservative GCs) in almost all situations.