Sure, you're giving up a fair amount of "shootability" and a marginal amount of capacity in the process though.
I'd agree with that when comparing a PM40 to a PM9.
I think the PM40 is just too small for good amounts of practice to be tolerable.
Shootability is relative - the 40 bothers some and not others - in a pistol larger than the PM's I don’t think I'm giving up a fair amount of anything with 40.
I shoot my Glock 27 more accurately and rapidly than my PM9.