the advantage of pulling an extra 0.1 or even 1.0g is miniscule and only beneficial if the obstruction is within a few metres of the aircraft when the maneuvre is initiated or the A/C is at very high speed. Overwhelming majority of GPWS incident are at low/medium speed. Modern GPWS will provide hard warning well outside the envelope where g is likely to be more useful than alpha performance.
The advantage of being able to accurately pull max alpha is huge and much more likely to prove beneficial.
I don't think I associated g meter and alpha. The point of my post is that they are separate and one (the one that A320 allows you to utilise much more effectively) is much more useful than the other.