As @Daggett said we had an issue when spawning large amounts of objects but that issue should be fixed. But maybe you have a lot of code in the init() and final() function of the objects, and in that case it might be more expensive to delete and create than it is to pool the objects?
You should also check the following answer from Ragnar regarding object pooling etc: Objects pooling for Factories (SOLVED)
Finally, if you need to get hold of any data that you can access from the profiler for tracking purposes then you should check out this post: DefPro - Accessing profiler data in Lua. Martin Noretoft from your office should already be looking into this if I’m not mistaken?