How long do you all get out of your motors before you retire them? I've been running my current setup for about 6 months. I flew about 12 packs today and they just didn't feel the same. The punch wasn't there and I felt myself getting to full throttle very quickly...

Keep them clean and oiled and they will last a long time. I have some 5 year old Sunnysky motors with many hours on them and they still perform as new.

It could also be your battery not the motor, Or motor bearings, Every part loses its punch with use.

Normally as long as the motors don't get too hot (over about 160-170°F) they will last a very very very long time. Just replace the bearings once they get worn. I've replaced bearings but never a motor because it feels like it's lost power. But you could also bend a shaft or a bell. Tho as long as they are good quality motors with good quality magnets and don't get to hot they should last a very long time.

I would guess that your batteries have seen better days

I'd point at the batteries too... A good slow balancing charge procedure every now and then helps getting some punch back.