I absolutely LOVE my 484-1. My collection is modest, but it's almost unbelievable how incredibly smooth and delicious it is to flip and operate.
Our frame of reference dictates how we opine about such things, so, to just add data points, my collection is:
Spyderco Domino {Brilliant knife. So great.}
Zero Tolerance 0770CF
Zero Tolerance 0450
Benchmade 0550 SHG Griptilian
Benchmade 0556BKSN Min-Grip; custom scales and clip
Benchmade 484-1 Nakamura CF
CRKT 5460 Ikoma Fossil (3.4" Plain edge)
CRKT K415KXP Ripple (3.1", black aluminum scales)
CRKT 6450K Drifter (G10)
Kershaw 4030TIKVT Nura 3.0
Kershaw 1620DAM Scallion (Stainless handle, damascus blade)
I have the luxury of being able to hit a few blade shops in my driving radius to "play" with them, and have messed with most of the Benchmade, Spyderco, and ZT lines; even a Sebby. I tune my knives as needed for optimum ease of operability and blade centering and elimination of blade play if needed.
So, all of that said, the 484-1 stands as the king of the hill IMO. Just wonderful. The ergos, the jimping, the all-but frictionless pivot that allows the blade to gravity drop with zero input, effortless operation, all of it.
(I'm also a watch nerd, hence the combo photo)
EDIT:
On the thumb studs - placing them outward on a bit of a thumb ramp adds to the mechanical advantage from an engineering perspective. The greater radial distance from the pivot, the lest force required with your thumb to deploy the blade. I think a thumb hole would both detract from the aesthetics and reduce the operational easy of the knife. It really is brilliant.
