I have had some tuning problems on my Blaster when running a pod filter attached directly to the carburetor. That said, it may have been the carburetor's fault, not the filters, because I never did find the correct needle for the carb I was running with the pod filter. Rather, I had my engine ported and went with a bigger carb/CFM airbox combo later on.
Lots of Banshee guys (myself included when I owned one) run/ran a set of pods directly on the carburetor, and the engine runs just as well (if not better) than with the factory airbox.
If you choose to run a pod filter, I strongly recommend using a water-repellant Outerwears filter wrap with the filter. Uni or K&N pod filters work well. Avoid paper filters, as Blaaaster said.
If you want a K&N pod filter to try, I have a new one that will fit stock and 28mm carbs, which Id sell you for $ 15.00 shipped. Shoot me a PM if interested.