User blog comment:Esoteric Arcane/new game - infiltrator/@comment-1341687-20120808060838

If you want a good Infiltrator build, look at my User page. The main thing you will want is to level up your Pistol all the way. With proper leveling of Infiltrator to Commando and that, you can essentially replace your Assault Rifle with a makeshift Sub-Machine Gun. Hit Marksman, shoot until they're dead and as soon as Marksman has run out, you can start it again immediately.

Infiltrator is how I did all three games. My bonus power was Barrier for Insanity because it became invaluable when forced into close combat. Combined with Immunity, I was a Biotic God.

All abilities listed on my Infiltrator were up to 12 except for Electronics and Decryption. They were only to level 9, but that was good enough. So the only thing to "suffer" was my shield amount. But like I said combined with Barrier, no worries.