I don't know if this is a newer mouthpiece or not. I got this Pax from an online store that still had previous stock, so I can't be sure how far back this one goes, and nothing to compare to. I guess I'll find out if it starts getting stuck. I plan to keep my Pax as clean as possible.
I've had several sessions exclusively with the Pax since it arrived. I have found my favorite way to use it so far is to load it up, set it to high, get it going, put it on my ion using a rubber cap, get one or two good solid, milky hits, push the mouth piece to turn it off, put it back on the rubber cap to get one more good hit from the bowl. The cap almost seals around the cone part of the mouth piece, even when it's inside the casing. It allows me to get that last bit of vapor, and it cools the oven faster, so my herb doesn't stay up at temp as long. Then I return it to the charger, and wait a few mins to let those hits set in, and I get a green light pretty quick.