I have both and have zero problem with either.
I like the P939 better just because its a 9 and the ammo is cheaper.
Kobra Carry | HK
P7M8, P2000sk, P30s | Sig
1911 C3, P238, P938, P239, P232 | Colt
Defender, Mustang Pocketlite, 1911 | Rohrbaugh
R9 | Kimber
Covert Ultra II | Browning
HP, Buckmark 22LR(suppressed) | Walter
| PPK(German made 1966) | Kahr
PM9 Black Rose | S&W