chips.

Ok - someone please tell me what's up with chips.
I have a vr6 w/ just over 200,000 km's on the clock, a prm intake and a no-name catback; would a chip be a waste of time, danger to my engine (which is serviced regularly and runs on synthetic) - and most importantly, would i even notice a power increase or difference in power curve on such an aged engine?
and if so, which chip offers the best performance for the price? from reading around (again, just websites/forums) people tend to lean to the garret chip, opinion? knowledge? anything would be helpful.
thx!
~spoonie