Best use for Fast TM?
For use in raids, I have little to no interest in upgrading to spend 30 minutes taking down rival gyms just to give another team their 50 coins for the day.
Tyranitar with it/crunch convert to bite/crunch
Gyrados with bite/hp convert to dt/hp
Snorlax with zh/hb convert to lick/hb
Golem with ms/se convert to rt/se
Answers
They already are…
I made the mistake of sticking my (formerly) top defenders in gyms where they have been sitting for three days, earning no coins. Of course, if I were a shaver, I could use my secondary account to collect 50+50 with little effort. The new meta is a perfect set-up for former shavers. Call it cancerous, I'm just trying to adapt to the new meta, which means defenders don't matter, and attackers for raids are the be all/end all.
I was going to suggest Tyranitar as well. I actually used a TM on mine today to change to Bite.
My second choice (and the one I plan on doing next if/when I get another fast TM) is Golem for RT.
Others might disagree with this. But I wouldn't consider using a Snorlax with Lick in a raid. I never used mine when attacking gyms in the old system because it simply took so darn long to faint the defending mon. In raids, you have very little time to finish. Lick with its low damage output and HB with its long cooldown really chip away at those precious seconds. If I'm wrong on that, someone please enlighten me.
I agree, I'm still trying to figure out which attackers generate the most rapid dps, since timing out is a bigger risk than having all 6 of your mons faint. I guess looking at the Blissey kill guide and going for the fastest, least potion efficient mons that are SE against the raid boss will shed light. I assume GP will update the attacker tier list eventually since survivability has become far less important than speed of kill.