I'm very particular about mouthpieces and hate with a passion the style that Hog comes with. I hate most mouthpieces on stock regs. I buy the style I like by the bag every year or two... They are consumables and sometimes they break, but at $3 or so, and 2 minutes to change...
Hog are nothing special, I've never found a mouthpiece that wouldn't fit.
+1. Cant stand the HOG el cheapo mouthpieces and swapped it the day I bought my reg.