I'll reinforce what others have said: two sleeping pads (at a standard 20" each) will be slightly overlapping inside with the floor clipped up. Certainly do-able, but if you're planning to use it with two people most of the time you might take a closer look at the Double. The Rainbow is very spacious and convenient for one.

Quote:
Does the clipping bathtub floor actually work?

Yes. It won't help you when you've camped in a "dry" wash and a summer monsoon decides to have some fun with you, but then again in that unfortunate circumstance a traditional bathtub floor won't help much either, and a wet sleeping bag is the least of your worries.

The clip-up floor was an evolution of Henry's shelters. First they were floorless, then sewn-in floors, and then (responsive to comments on boards such as this one) Henry added the clip-up floor. I like the flexibility of it. In hot or humid conditions, it stays down, and if it's pounding rain (or you just want to feel enclosed) you snap it up.

Or if you have two people, you leave the floor un-clipped to take advantage of the extra width (46", I think, vs. 38" clipped).