I like RAT as a company, and I think their services are great, but I have used both RAT Cutlery (RC) knives and the Ontario RAT knives, and to be honest there is no significant difference in quality. There are minor changes, but 9 out of 10 people would not be able to tell whether a new knife in the series was made by Ontario or RAT Cutlery. If you want to support RAT Cutlery, then buy your knives from them; if you want to get the same quality for a much lower price, go with the Ontario version. They are both 1095 blades, full flat grind, with the micarta handle. The only actual difference that I have seen so far is that the RC 3 has a longer handle than the RAT 3.
Sorry to ruin the party, but until someone can point out a difference that I have not been able to detect, I must go with Ontario just because of the lower price.