I hope I'm wrong but I believe if and when eth goes POS, gpu mining will stop being profitable for most people.  Right now most gpus are hashing eth and when that huge hash power is turned to other coins, their difficulty will shoot up and profitability will plummet.  I can't see any other alternative to this happening.  I doubt we will ever see a bull run like this again for gpus.  But it's been a wild ride