This is a hit or miss issue. AS with any mod of course. However, MAF's and larger TB's have a 50/50 success/failure rate.
The stock MAF is actually a pretty well tuned device from GM. It's quick to adapt and learn and can pretty much supply the needs of pretty much anything you have done to it. The ZO6 MAF is what I would consider also A "stock" MAF as it is a GM MAF. Hence, the success with it. Others like GMS's I wouldn't waste cash on.
For what it's worth, if you don't think the stock MAF is good enough, talk to many power adder owners such as myself (heads and cam, stroker, blower/nitrous) and most you will see retain the stock MAF. I'm running a stock MAF on my built LS1 in the Camaro (which has surpassed the 400rwhp mark)! It has yet to outflow the needs of the LS6 intake and stock TB and is actually better for tuning with such programs as LS1Edit.
People get all wrapped up in one number...how much it flows over another and that isn't the sole measuring point. More airflow means it'll run it leaner temporarily which is where the power gain is seen (and qouted by the makers) but after the PCM learns and adapts for it, power returns to virtually the same levels it was with the stocker.