Don't worry about the overpowered thing - Marines will always be that.
If your heart lies with Ultra SMurfs, do them, Blue is a good colour to paint.
I always say choose an army on looks and fluff, the army list will sort itself out. You dont want to lustfully be looking at an Ultra Marine army thinking "why didnt I do that".
And besides rumour wise it'll be a while before Marines get a redux, they may not get one until the next lot of rules.