Depends on what you're doing with it. Their system only applies to V8s (I saw a similar post on slantsix.org, so I wanted to check what you're up to) because they're using a 5.0 Mustang ECU. They generally fire up and run out of the box, but you're not going to get a canned tune that will get you as good performance as a tune set up for your engine, whether you go with a speed density or mass air flow ECU.
Their MAF is a bit of an interesting one - it's not a recycled GM part, and they've done a pretty clever job at packaging it. I've also got to give them credit for the shear variety of port intakes they offer.