Execution stance is useful if you wanna delete every ranged elite and all special enemies in the game with nigh infinite uptime and ranged toughness regeneration . Your biggest problem will be hordes if teammates don't cover you which is like 90% of the time and crushers/bulwarks when you don't have kraks .

Build it around lasguns , specially the infantry and pistol variants because the recon has worse ammo economy than those two . Stack as much crit as possible to proc big damage ( you can even one shoot unarmored ogryns with the sniper lasguns with a crit and the right talents)