For 2010, the only problem I know of is the seat warmer that has a tendency to drain the battery even if it is not on and the vehicle is powered off.
Make sure THAT has been fixed in the one you buy.
I have searched the forums and have found one or two isolated threads. My question is, is there one place where the TSB's are collected and are copies available of the TSB's? If there is one, I haven't found it yet (should be a sticky somewhere). Thanks.
Here are two links to TSBs' although I do not think that the seat-warmer TSB has been publicly released or posted in any website or has 2010 MY TSBs updated yet.
You can check if they are any recalls or if any come up if you register with Mazda's Owner website. As far as TSBs I am sure they will start to trickle in as time passes.
Recalls = Safety Related Repairs covered fully by car manufacturers regardless of mileage.
TSB = Technical Service Bulletins that are released to Technicians as aids to resolve common complaints that arise as a mass production defect from factory or issues that seem to come up among owners. These will only be covered free of chanrge under warranty but can be performed after warranty period at owners expense.