I find Nak and Boomer to be the hardest to use. I recommend using an easy, basic bot (ex: Mage), then moving onto high angles (Ex: Turtle, Kals). If you're up for the challenge, Boomer is alright, best with laser.
well i think you should use the mobile your good at before you quit. i quit gunbound too for 4 months when i tried to play gunbound again im not vey good at it anymore i was really dissapointed because i couldnt keep up anymore i tried to use the mobiles im good at for 1 week and im back in playing gunbound again