Mac Snow Leopard vs Lion

I believe my PC laptop has seen its best days so I’m thinking about switching over to an iMac (2.5GHz quad-core Intel Core i5).

Some dealers offer it with Snow Leopard and some others with Lion.
Does one work better with Cubase 6?

I’m not familiar with Mac but everything I read indicates running music applications is much easier. This computer will only be used to run Cubase and my external keyboards/modules, mixer etc.

Thanks for any input

Cubase is fully compatible with Mac OS X 10.7 (Lion), the only thing you might want to consider is that Lion has dropped Rossetta, which means that Power PC software will not longer work on lion. That can affect some of your plug-ins, also make sure that all of the other components of your DAW are compatible with Lion.
At least I can not see any performance difference between Lion and Snow Leopard.
If you need more information please read this knowledge base article.

Best regards,