I got Blurr, Kup and Jazz.
I prefer the Combiner Grimlock, so didn't feel it was necessary to buy the Studio version.
I have a customised Titan Returns Hot Rod remade to be a Targetmaster, so didn't need his Studio version either.
But I don't think that is Hot Rod, I think he is Rodimus Prime.
As far as I know, the way to tell is to look at his legs, if they are not bright red, it's Rodimus you are looking at.
I would prefer a dedicated G1 Studio series, so we know we're getting characters from the original show.
Presumably they'd release ones they haven't already.
Although my wishlist may be impacted by the fact some of them already came out, but not precisely in true G1 format:
Mirage (Combiner Wars and cybertronian form), Hoist (his design is a little kibbley to me, so want to see if they can do better without the ramp master gimmick) and Red Alert (cybertronian form)