My capsules only get used when I take my F2 out in public, like a park or the beach. So mostly in the warmer weather. The mp is quite stealthy and you can pop capsules in and out of the F2 quickly and easily. Otherwise I'm using the glass adapters most of the time around the house. That would be the bubbler or the wpa. I like the cooler airpath and they keep the heater chamber clean.