I have been running without a maf for about 20 years. If you have no emissions inspections, no visual inspections, etc. as I do. It works fine. I am currently running the SD-1 chip.
I am perfectly happy with the set up. I am running a T66 bb turbo with an S housing and a 4.0" inlet pipe. My imagination says it revs quicker under no load.
Performance-wise, it runs the same as it would with a 3.5" maf. This is the first thing people have to understand, unless you have a car in the low Tens, or possibly even the Nines, there is nothing to be gained by going from something like a conventional TT 5.7 chip to a 6.1 chip, to an SD2, or to an XFI aftermarket set up. Yep, that is contrary to the advertising thrown up by vendors and tuners, but, history has shown it to be true over and over over the past 25 years.
I would like to throw in a special shout out to the XFI-Sportsman. It is the greatest crock of shit ever foisted off on the Buick community. Yep, you can install it and start the car, but, it will not run worth a damn unless you hire the guy that sold it to you, or someone else, to tune it to your car. It was a marketing gimmick and if you spend some time reading, you won't very many happy customers but you will find some used systems for sale.
Back to what I was saying. There is no performance gain coming to you out of the box with any of the systems if your car runs only tens. A 3.5 maf and a modern chip is capable of doing that virtually on the default settings of the chip as it is delivered. You can tweak it a little leaner and get a bit more out of it, perhaps, or making it launch a little harder. Personally, at this time, I think the TT 6.1 with a wideband O2 installed is the safest, simplest chip available.
If you have money to spend on a big turbo, matching converter, IC, heads, etc., and you want to top it off with an aftermarket fuel management system to have something to talk about, Then spend $1900 on the ECU-GN offered by TurboTweak/Bailey Engineering. Like the others, it will actually cost more by the time you add ignition bells and whistles to it. The upside is that it is built specifically for turbo Buicks on top of a MegaSquirt 3 fuel management system that has virtually every bell and whistle known to man today built into it but you can plug it in, and drive the car away and take it to cars and coffee and not be afraid of it not starting or running right.
Jason Goodwin has one. He can extol the many virtues of the system but, he will not tell you that it will convert your car from a slug to a rocket or leap tall buildings in a single bound. Neither will Eric/Bob. They are too honest for such.
If you are like Jason, or probably me before I got old and broke, these high end systems are fun to play with if you are technically oriented, but, they are not magic. They may add hundredths to your performance but not tenths. Walt Judy ran in the lower Nines on a MaxEffort chip which was the predecessor to the TT SD-1. But, to have fun playing with the systems, first you must learn how they work, what the parameters mean, when you may need to tweak one, and what not to do to blow your engine up by messing with the wrong factor. Chips from TT or Bob make it much harder to so.
THERE IS NO MAGIC FOR SALE IN A BOX THAT WILL TURN YOUR CAR INTO A MONSTER FROM ITS NORMAL PERSONA unless they start discounting boxes of money when you buy in volume.
Oh, yeah, the 3.5 LS1 maf will flow more air than a stock factory maf. That might be beneficial in the low Tens. The main benefit is reliability. The factory style mafs are fragile and may not last a long time. The rebuilt units are often not calibrated the same as the original turbo mafs, and some of them are just completely wrong for the cars. This is one of the areas where you do get value for your money. Just don't expect it to be faster than your original factory maf was when it worked right-unless you are into the tens, then you might pick up a little on the top end.