After much testing I have decided that the overall best CQB weapon to use is P90+laser+suppressor (optional), or MP7+laser+mag. All other weapons have significant shortfalls which make them sub optimal. You can try switching the laser for taclight but I find it's not as reliable.
Rifles & carbines: you either use heavy barrel for the aimed accuracy or laser for the hipfire accuracy. With the HB, your hipfire accuracy is extremely bad which means you have to rely on aimed firing. In tight quarters this can be hard to manage. With the laser, your hip fire is still worse then the SMG's, your aimed fire is worse (especially when moving), and your magazine size is still limited to 30. If you really must use a rifle or carbine, stick with F2000 or MTAR. They have the best hipfire accuracy, TTK, and bullpup movement speed bonus.
Shotties: the auto shotties have too short a range to be reliable. They are nice up to 10 yards but areas like C flag on Donya are problematic. Also, slow reload speed. Semi-auto shotties with slugs are 1-hit killers, but if you miss with your first shot you are dead. They have a slow TTK if you miss. Also problematic for multiple enemies.
Sniper rifles: worthless except maybe the M417. With a laser it plays basically the same as the shotties with similar tradeoffs. Good for long range and point blank, but nothing in between which is where 75% of gunfights happen.
SMG's other than the recommended ones: UMP, PP2000 - fires too slow. M5K - smaller magazine size and worse recoil than the P90/Mp7 with less hipfire accuracy. This gun offers zero benefits over the others except for less side-to-side recoil which is irrelevant at close ranges. I thought it had better aimed accuracy but that was just my imagination, it's the same. AS-VAL - bad accuracy when moving and bad hipfire accuracy. This gun is meant to stand still and take careful aimed burst shots at long range, not close quarters, although it is still not bad due to the high rate of fire.
LMG's: LMG's have extremely bad hipfire accuracy and not very good aimed accuracy, making them worthless for these maps. Don't even bother.