I read an article about the 2nd generation stuff from Ontario. In that, it was discussed that they hired a new guy to oversee the procduction of these knives. Part of his presence was to get the heat treat right.
I had their Kukri and still have their Survival machete, bothl 1st generation, and they have a good HT. (read, they hold an edge) But, I also have 3 RD series Ontarios. The RD Hawk is good, for a tough hawk, I can get it sharp. It's the RD4 and the Afghan that are too soft, they don't get that sharp, and they both dull pretty fast. Those two are supposed to be 5160, and my experience with that, is that it should take and hold a great edge.
So, I'd be concerned with the RAT stuff, because the quality control wan't there. That's why there was a split in the first place. With ESEE you aren't just getting better F&F, nicer sheaths, but you're getting the correct HT for the steel used.
I like certain products from Ontario, but they make so many products, so many different steels and HT's, and at least some portions of their operation is mixing up steels or just not doing the HT correctly, IMO.