I used to have an Xs20 crash and ride. so far the rock models of Xs20 are better compared to the mediums.
The Rock Xs20 has a stronger & more defined Bell, since this model is built heavier, they produce more wash but it's release is shorter compared to the mediums. I'll definitely go for the rock models of Xs20. Buying the cymbal package comes a free 18" crash...i don't know if it's still available.
Xs20 cymbal model is more of a blending cymbal...it's not like the cutting cymbals you hear on casted models like (e.g. AA, AAx) and to those sheet cymbals (e.g. B8 and B8Pro).
The good side of Xs20 is their durability and affordability considering that this cymbal line is casted and made with B20 bronze(said to be the most or if not one of the most expensive alloys).
The Pack also comes with a cymbal bag and expanding on this model is easy. They have a splash and a china, both sound sound decently.
But if you have a a bigger budget, try considering AA models. Most Rock drummers and heavy hitters prefer this model because of it's cutting ,explosive power and durability.
Goodluck there bro. Hope this helps.