Fordtough25
Grandmaster
Ive owned both and as a matter of fact I bought a G30 after already owning a Sig 220 SS Full size. The sig had the best trigger I have ever felt on a handgun. It would be a great carry gun on open carry. I sold the Sig after I bought my G30 because I hardly ever shot the Sig after i got the G30. The Sig was very heavy (SS) and large frame (think Ruger P series).
A G30 will accept G21 10rd mags. For Concealed Carry the GLock 30 hands down!
It will accept the G21's 13 round mags also.