The needler pistol serves as an excellent mid to late side-arm that offers more damage than even the Gauss pistol against lightly armored targets, albeit requiring the use of semi-rare and expensive ammo.
With the AP Ammo, this weapon is surprisingly deadly and very accurate.
The Needler has an extremely high critical damage for the time you can first acquire it. Sniper rifle criticals will go up to 80 damage, but the Needler will critical for 130-180 at a distance of five or fewer hex spaces.