I have SPLAT. I upgraded from Melodyne Essential to Editor. Since doing so I have been using Melodyne in the effects bin instead of as a region FX. I use it first, correct any pitch issues then bounce it to another track. Then I archive the original track in case I ever need it again. I have only used it on vocals so far.
The question - are there any advantages or disadvantages to using it in the effects bin or as a region FX? Does it really matter? The end result is the same. Just curious.

Persoanl choice IMO.
 
I used to use the FX bin. Now I use ARA. That's my comfort level. YMMV.
 

I haven't used in in an effects bin in a while but using it as a region effect for me is quicker as you don't have to record or import the audio it just comes up.