Skip the Rat 3 and buy the better made ESEE-3. It's the same knife with a better heat treat and a better warranty (lifetime, unconditional).
Randal's Adventure Training (RAT) designed the RAT series of knives for Ontario. There was a dispute, so RAT Cutlery split from Ontario and started selling their own knives (same design as Ontario, but built at Rowen manufacturing) with an unconditional lifetime warranty. There was another dispute over their name, so now they are ESEE Knives.
The ESEE-3 is a fantastic knife. I have 3 of them, and use them constantly. I wear one almost every day, on a Tekok under an untucked t-shirt.
If you are going to pocket carry, get the version with a rounded pommel, it will be less likely to rub a hole in your pocket than the spikey standard pommel.