Just as an example, guys tend to hit fuel cut on a 1G/GVR-4 MAS on the stock turbo at 16-18psi on a cool night (with no injectors/fuel control to fool the ECU). Compare that with a 2G MAS, which has gone 10s in the 1/4mi. You're realistically looking at 2600+ Hz and 50lb/min before the 2G MAS starts dropping counts. I like knowing my MAS is still accurately metering the air at close to 500whp.
In addition to the higher MAF count capabilities, the 2G MAS is far less restrictive than a 1G. Is it still an intake restriction? Sure, but at the 300-400whp level, I doubt it's huge. If you're going GT30R or bigger, I'd start thinking about a GM MAS. Otherwise, the 2G MAS is a great, inexpensive upgrade.
You will need some sort of fuel control to compensate for the difference in MAS calibrations, however, as 1G cars tend to run a bit lean since the 2G MAS flows a good bit more. I think some guys just strap on 550cc injectors to compensate, but I'd recommend an AFC at a minimum.
Bill