The biggest “performance impact,” obviously, is going to arise from there being millions of just-about-anythings, all in memory, all at the same time.   Simple page-faults are probably going to eat up both your breakfast and your lunch.   You can get away with this sort of thing if you’ve got gobs and gobs of real RAM, and a 64-bit environment, but the design here is IMHO inferior.   If you can possibly reduce that memory-footprint, I think you’ll be very glad that you did.

bless(), by itself, has very little impact, as has been shown.   But what’s kinda scarin’ me is the thought of all those method calls.   If you really do intend to have three million things in-memory at once and for those things to be objects that are all “really, highly-active,” this is a design that’s really going to be fighting some uphill battles in terms of performance.   Can this really not be simplified in some way?