I'd rather not cut into the passenger compartment. I'm not going to seriously race the car, I just feel that with the upgrades that I am putting into the car I would feel a bit safer if my frame was connected.
I will admit that cutting the floor is a bit aggressive, especially if you are building a street car. Ours is being purpose-built for the track only so I don't have any considerations for fitting carpet, seats, etc. The Crites units would probably suit you better.
I will note though that while I was jacking the car up today, with the jack just ahead of the driver side connector, that as soon as the left front was about 6" off the deck the passenger front started coming off the floor as well.
Mine may not win the pretty award but they do work.