Chastity and orgasm denial discussion

I’ve been thinking about getting a device for a while and now I’m back to see if the PA-5000 might be exactly what I need… I currently wear a PA with either a 4ga or 6ga ring. Last night I measured my cock and think it’s around 1.25 inches, which matches the largest size for the PA-5000. However, they recommend going one size up (by about an eighth of an inch) to ensure a good fit that still allows for cleaning. So what do you all suggest? I’ve read online that everyone says go smaller for a tighter feel, but I’d love your opinions… Please advise! Who knows, maybe my measurements changed slightly while I was measuring up! I haven’t worn chastity before, so I don’t want it too tight or painful. Thanks in advance; looking forward to your advice so I can place the order.