They'll certainly get your attention soon as they go bang that's for sure. Even with hearing protection they're a loud little mofo. For me it's the pitch or tone that is most noticeable because it's a very snappy crack that I notice the most and without pretty decent hearing protection actually hurts my ears. I have a Ruger single six and shooting 22mags in that is very similar and is LOUD AF but I like shooting my PMR30 wayyyy more.
The PMR30 isn't going to win any beauty awards because they're kind of a fugly little thing and like was mentioned they have a pretty fat grip but for a backpacking gun that holds a lot of rounds in one mag is still pretty LW even loaded with 30rnds and is really easy to shoot IMO they're about as good as it gets.
Visually that big grip gets your attention as soon as you see one and the first time you pick one up the fat long grip may feel a little odd but because these things hardly have any recoil, even for little hands, they are so easy to shoot. First time I handed mine to my wife she handed it right back and said the grip is way to big she didn't feel like she could comfortably get her hands around it to hold on to it but I was able to talk her into just giving it a try, now, of anything we have it's easily her most favorite gun to shoot.