The shape of the M800 Ultra is best described as a uniformly scaled-down Razer Viper. The M800 Ultra is a decent bit smaller, but other than that, everything is there: low-sitting hump, similarly flared front and back, curvature of the sides, and fairly deep comfort grooves in the main buttons. That said, the hump appears slightly more tapered than on the Viper, and the rear is not as wide relative to the front. Aside from these minor differences, the M800 Ultra is clearly a Viper in look and feel, so anyone familiar with that shape should have no trouble getting used to the M800 Ultra quickly. Compared to previous releases of the M800, the only difference is the lack of texture on the sides.
As for grip styles, I'd say the M800 Ultra is generally suited for claw and fingertip grip. It is a medium-sized mouse with a barely pronounced hump, which makes it generally suit most hand sizes. For reference, my hands are 19 cm long and 10 cm wide, and I found the M800 Ultra very comfortable in claw grip.
Dimensions
This table includes the dimensions of the DELUX M800 Ultra and several other ambidextrous mice. "Front height" denotes the distance between the base and main buttons. Measurements with two decimals have been taken with a caliper, while those with one decimal have been taken with a ruler. For a full list of all measurements taken, please refer to this sheet compiled by an esteemed community member.
DELUX M800 Ultra Dimensions
M800 Ultra
Cobra Pro
Viper V3 Hyperspeed
Atlantis 4K
X2
Base Length
11.0 cm
10.5 cm
11.5 cm
11.7 cm
11.4 cm
Length (including overhang)
12.35 cm
11.92 cm
12.69 cm
12.33 cm
12.02 cm
Front Height (lowest point)
1.1 cm
1.1 cm
1.1 cm
1.1 cm
1.1 cm
Height (highest point)
3.78 cm
3.77 cm
3.91 cm
3.80 cm
3.74 cm
Front Width (widest point)
6.15 cm
5.88 cm
6.23 cm
6.16 cm
6.12 cm
Back Width (widest point)
6.38 cm
6.18 cm
6.37 cm
6.59 cm
6.33 cm
Grip Width (narrowest point)
5.93 cm
5.54 cm
5.99 cm
5.96 cm
6.02 cm
Below are some comparison shots with each of the measured mice: