I really like it. The action on mine is great and it feels like a beefier (handle width top to bottom, not thickness) 0460 with a better blade. The width is about halfway between the 0460 and the 0770, I think. I own some 0450s and 0460s, and I like the feel of my Tumbler better already.
It does have sharp edges on the G10/CF handles out of the box, though. It was a bit of a pain to take apart and sand down, though I did so on the two hour conference call I was just on. It's sort of a little jigsaw puzzle where the back spacer, the piece the clip screws into and the handle slabs meet, but it's the frame screws that were the annoyance--on mine they spun in place as a free floating unit (barrel screw one the presentation side and the far side inner screw all spinning together) so I had to use two screw drivers to get those two loose.
After breaking all the sharp edges with a couple of minutes of quick sanding the knife feels ten times better in hand. The clip tension on mine was a bit feisty as well, especially landing on the texture they have milled into the CF, so I bent that out ever so slightly as well, but I'm really happy with the result.