Hey 
Is there much difference in quality between GA4 metal/rock packs and others VST i.e. Steven Slate Drums?
Tell me your opinion please.
It depends, some GA expansion packs contain new samples, some don’t, the metal essentials pack uses the standard accoustic agent kit but with a new set of (suitable to the genre) mixer presets. Accoustic agent sounds far better than thousands of records with the drums squashed to within an inch of their life, but they are not, in my humble opinion, up there with the best other drum VSTis. Some additional GA kits do sound fabulous, such as Nashville and (particularly) Simon Phillips. Of course, if you only have the default Groove Agent SE then the accoustic agent kit is a lower quality still.
I do find GA kits tend to sit in the mix nicely - perhaps having the best possible sounds isn’t as important as it first seems.
I have GAse and I would like to expand the kick and sanres samples options. What solution could be good for me?
Another Vst Drum? which one? Thank you. Mostly Rock and metal sounds.
There are so many options it is just not funny.
Personally I love BFD because I can also use it in conjunction with Drumagog.