If you like a Mora, odds are you will love the F1 - unless you just plain don't like good knives.
MRPink said the RAT-3 has a good handle for small/medium sized hands. Trust me when I say this: no-one has hands so small that the F1's handle would be uncomfortably large for them.
The F1 represents Scandinavian knife design, with the same mentality as the Mora, except just about a million times superior quality. It's a working knife, and a tough one, but still has a geometry that you can work with. The RAT represents the tactical knife style, with a pointless, huge choil on such a small knife, eating space and making precise cutting work difficult, and making the ergonomics of the knife that much worse. I would take the F1 without even considering the RAT. But that's just me - your mileage may greatly differ, although if you like the Moras, I don't see why it would.