Blade:
The shape to me looks kinda odd, possibly from the gut hook. Gut hook works fine. The blade near the tip has been used quite (and I mean quite) heavily, and took a while for me to put a good edge using the 204. Nevertheless, it's a great cutter that most VG-10 knives from Spyderco are. Cutting cardboard is no problem, while penetrating requires a bit more effort (granted the knife isn't designed for that). Hollow grind certainly suits the task it's designed for.
Handle:
It's quite comfy. I don't see how the fit and finish is that sloppy. The G10 is well textured, but not as rough as my Starmate. It generally has a good grip, but again, I find the handle shape a bit odd. It just looks odd, but doesn't affect how well your hand fits. I normally like to choke up on the blade when it allows, and the Impala is designed with a choil right at where the blade and handle meets, like the Native.
VW noted that the tang sticks out of the handle, but normally it doesn't quite matter. I get by with my Starmate quite well, where a significant bit of the tang sticks up.
Lockup:
Here's where the trouble begins.
Right hand lock up is very nice. I found the liner to be very springy and tend to lock up well. However, it's fairly easy to disenguage the lock if you're using it left handed and twisted the blade. I did that a couple of times sticking the blade into cardboard. however, the same problem couldn't be said for the right hand. I think Spyderco ought to make the liner less lightly to be caught open when being used left handed.
Overall:
It's a nice knife, works very well. However, it just looks kinda oddball to me. I think the primary issue for Spyderco is to make sure that Impalas won't be closing on leftie's hands.