should i buy this? http://www.euro-yo.com/acatalog/Pistolero_.html or is it a upgrade to my dv888
You could have just asked if you should get the Pistolero II, but whatever.
It is not an upgrade from a yoyo. It is just as good as the DV888 (or most other yoyos), just different. If you like the specifications (size, shape, weight…) of the Pistolero II, then you should be happy with it.
Like Ape said, totally different yoyo. And yes, if it fits your preferences, get it.