SIG's X-Carry medium sized grip modules are very close in diameter and depth (front to back) to their standard grip modules. The X-Carry modules feel (to me) more rectangular, with the standard modules more rounded. Having said all that, if you're going to build the Carry version (full-size magazines with compact length dust cover), consider or at least look at, the Wilson Combat Carry II module. WC grip modules do not have various sizes, but I find them more comfortable and hand-filling than either of the SIG modules. I have a P320 Compact in .357 SIG and a P320 X-Carry in 9mm, both have WC grip modules. I built the .357 SIG from components and started with the WC grip module. The X-Carry came with the SIG X-Carry medium grip module, so I was able to judge the differences in feel between the SIG and WC grip modules before I ordered the WC Carry II grip module. I wear a large size glove.