I used the Tempest a majority of the time, but I just got the Locust last night. Tempest is hard to beat when it's lvl X. 90 round clip, 430 spare ammo. Can still have +200 charge speed bonus, since it isn't heavy.
Locust is great for the instantaneous reload time. Worth the weight increase. I have like 70 spare thermal clips, so I think I'll stick with it most of the time, even though it is lvl I.
I just keep a constant steam of shots toward enemies between constant bursts of powers. Seems like a lot of people carry heavy or multiple guns. It doesn't seem worth the weight increase to me. This game is a lot more fun when you focus on your powers imo.
But I have had enough good teammates carrying heavy Mattock or Widows, sometimes with another weapon and they pulled their weight, so I can't complain. Games have always been much better for me when I have a good sniper on my team. I haven't really tried the sniper rifles too much, I probably won't spend too much time with them. It's just nice that different playstyles can compliment one another as long as you use teamwork.
Im sorry but Im not equipped to reach a conclusion regarding that assessment at this time and whats more let me add that Iwill explode your head for saying that
Carnfiex in general Widow for Infiltrators Katana or Claymore if you had to use a shotgun
I find Assault Rifles are pretty meh for but I don't have the last one, Reveant I think, to make the final judgement. I've not been impressed at all with the other ARs vs. other weapons though. Carnfiex covers as almost the same distance, more accurate and ridiculous powerful for a Handgun Pistol and you still get good lightweight bonus without feeling gimped in power. Things drop with 1-3 headshots even on higher difficulties.
Widow has terrible reload speed but the power is insane when used on Infiltrators with Cloak + Headshot bonus, 1-2 shots anything even on Gold and makes strong Cloak built Infiltrators Atlas wrecking machines (rips out like 4-5 bars per shot). The reload speed syncs with Infiltrators Cloak cooldown so it's not really that bad on them.
Claymore is like using a shotgun version of Widow but even stronger (and obviously less range), so far think only Krogan Soldier rocks it the best. Human Soldier can make it look good too if you use a lot of Adrenaline Rush animation clipping, insane burst damage then. Katana is more balanced in power, reload speed, and shots fired before reloading if you prefer an alternative.
Definitely agree with the Carnifex being the all around best. It's basically the Viper, but in handgun form, meaning less weight. With my Sentinels, Engineers, and Adepts I take nothing but the Carnifex for max recharge speed and power spam.