Using an 8 core MS Azure instance running Server 2008 R2. Works really well - I've got it for around 10 days free using their $200 free trial.
Best thing with Azure as far as I can tell is they automatically disable your account at the end of the trial period - they don't even try and bill you. Apparently they got a lot of flack in days past about that, so they've opted to default their trial to a $0 spending limit - so you'll never have to pay a penny if you don't want to.
They run Ubuntu 13.xx as well, but I've had compile errors with 13.04 and I love mstsc.