I called a major manufacturer of both kinds, water based (catalyzed) and oil based to get the hardner that is supposed to be available for water based poly. They told me that if I wanted a harder and longer lasting finish to use the oil based. I do agree that water based sets up and is recoatable and usable faster but I think that the oil based lasts longer.
Actually, the oil based probably stays a little softer and moves a little and that's why it lasts longer. I do also know that one of my kids had a room that had been carpeted for years and needed a fast and cheap clean up of the floor. We filled the tack strip holes, lightly sanded, layed on 2 coats of oil based poly with a light sanding between coats and that floor looks great. It's been 6 years since we did that and no delamination of the finish yet.
A spit coat is one part of a 3# cut shellac like Zinnser's Bullseye to 5 parts denatured alcohol. This is a very light mixture and you can apply it with about any kind of cheap brush you wish. One of the unpainted wooden handled, natural bristle brushes works great. With that much alcohol, you do need great ventilation during application. This seals the wood slightly so you get a more even stain color. You don't get the blotchyness that you can get with some stains on some woods and I even use it as a sealer on straight oil based poly finishes.
Other than that, Tom is on track as far as blending old and new wood floors. He and I are not the first to disagree here about oil based vs. water based poly and I doubt that you will change either one of us.