The LTI Impulse series was not specifically designed for shooters. I own an Impluse 2000 XL and an Impulse 2K. They have similar range and accuracy but the XL adds an inclinometer, some trig functions, and a serial computer interface.
Relative to some other rangefinders, the Impuls beam size is a fairly large.. It appears to be over 5 times the beamwidth of Leica 1600. Off of foliage It is reliable to over a mile and will often measure to it's computational limit of 2400 yards. Trying to range animals beyond 1000 yards and not measure nearby objects is not practical with any rangefinder I've used.
Unless I expect to be shooting at over 1500 yards my choice is the Leica 1600 which is tiny, light, and cheap compared to the Impulse 2000's.
Not that it concerns most hunters in the US, but a limitation of most rangefinders including the Leica and the Terrapin is that they're useless in low light. Either you can't read the diisplay, can't see the objects to be measured, or both . Because the Impulse scopes have a rail on top and an illuminated LCD readout in back a night vision scope (AN/PVS-4 or -12) can be used on the rail to measure distance accurately in starlight to objects without additional illumination.
