First off let me say I am not a microsoft hater...but I feel that Unix / Linux has some advantage over Windows products in some areas...... :ermm:
So if it was me I would go with the Linux hosting, all the same basic functionality and if they are any good at all 100% same functionality but Linux is hardened against hackers IMHO.
I host 7 sites myself and I only use Linux, never had a security breech and never had a site that wouldent do everythign a customer wanted.
Plus kinda nice to stick it to the man everyonce in a wile :gun_banda