Tactics MP7, Worth a slot?

[Steeps]

I always take it (except sometimes on Patty waves) since it only weights three blocks and helps make the medic a more effective healer. If I'm not going to heal and want to focus on another role then I'm more effective playing another perk. Same goes with medic armour; I buy it every single wave (unless I spawned with it of course) even though I often don't need it since it's dirt cheap and so effective.

The eleven remaining blocks are more than enough to provide a loadout that supplements the medic's role.

 

[Azukki]

MP7 is invaluable for medics. It more than doubles one's healing powers, and it can get the trash out of the way decently too.
Off-perk, it's not great, but it can occasionally be worth the 4 blocks and $90 it costs a medic. It's never worth the base price, though.

It can be surprisingly good as a weapon, too, if you keep the bursts short and accurate. A crowd of 7 gorefasts can be dealt with without reloading, without undue difficulty, even on HoE.

 

[CandleJack]

Katana, Dual Handcannons, M10, MP7, Syringe

An awesome weapon in all slots, with a purpose for each.

MP7 for ranged healing, Syringe for emergency melee heals, M10/DHC for CC and scrake/FP tanking/aggro stealing, katana for when guns are empty or when SHTF.

I do believe the MP7 will be supplanted by the M7A3 though; however for now it's the most valuable tool in the Medic's arsenal.