Normally, the anti-blooming chip, will have lower sensitivites than the NABG version. The exception to this is the technology used in the Sony chips. This works well in general, with little reduction in sensitivity (sensitivity does rise a little as it is turned off). Generally ABG chips, will still retain the problem that the linearity changes as you get close to the gate level (before it actually operates), making them less useful for photometry applications.
Look at:
http://www.newastro.com/newastro/default.asp
for a 'blooming removal' plug in.

Best Wishes