Read this...
Review: Biotest Carbolin-19...Is it Better than Anavar?
You can conclude Carbolin has promise but hasn't been around long enough to really see how people react.
I don't know anyone who has used it personally nor have I ever come across anyone on any forums that has used it.
At least anavar has a proven track record.
The best I can say is that give it a try and see if you like it!
Also....if something has been around for a few years it is still around for a reason. Alot of supplement companies come out with new supplements that don't even last 2 years because they just don't make a significant difference. Carbolin has only been around a short while. You may want to see if it stays around.