I'd go for the RAT-1. Feels more solid in hand, more comfortable to handle (especially if you have to put any weight into the cut), and arguably slightly better blade steel. The Tenacious has several good points too. The G10 handles do grip better, the knife is lighter weight, and the Spyder-hole is a bit easier to open if you're wearing gloves.
The Tenacious family just never really did it for me. While they're certainly not bad knives, it was just several little things that would bug me ever so slightly, and the effect was cumulative to where it would be just enough to be noticeable (not unlike the sensation of a small pebble lodged in your shoe). If you are considering these, I'd suggest spending the extra to get to the Dragonfly/Delica/Endura/Stretch instead. Those are all terrific knives in just about every category (great steel, compact, lightweight, solid-feeling, refined ergonomics, and just about everything else you'd want in an EDC knife).
The Tenacious family just never really did it for me. While they're certainly not bad knives, it was just several little things that would bug me ever so slightly, and the effect was cumulative to where it would be just enough to be noticeable (not unlike the sensation of a small pebble lodged in your shoe). If you are considering these, I'd suggest spending the extra to get to the Dragonfly/Delica/Endura/Stretch instead. Those are all terrific knives in just about every category (great steel, compact, lightweight, solid-feeling, refined ergonomics, and just about everything else you'd want in an EDC knife).