I haven't any of the calls listed, but do have two GVCC Triple X's and three C&S Custom Calls Apostles. I have one Triple X (chartreuse) and one Apostle (blue) on my lanyard. Each does things a little differently. The Triple X uses a bit more air, is a bit more "goosey" and works better at the lower pitched notes. The Apostle is .2" of an inch shorter, has a smaller bore and uses the GK Edge E3 guts, with the narrow end of the reed. It is a "screamer", a very loud call with very little air required to do so. But, it's not a call I would recommend to anyone who pushes a lot of air through a call. You'll lock it up doing so.
You might try, on one of your GVCC calls, using the wide end of the GK Edge E4 reed. It will allow you to push more air through the call and that usually translates into a louder call. You may need some new guts, though. GVCC uses KOD tone board and wedge, with the call maker's special reed, which is a bit narrower than the E4 reed. Another option is that if your GVCC call has a shaved reed, you can get an unshaved reed from the call maker and that usually will allow you to push a bit more air through the call, too.
First and foremost, though, a change in reed or guts is a lot cheaper than buying an entirely new call. I'd call the call maker (GVCC) and ask him what he would suggest doing with the GVCC calls you currently own to make them louder.
Of course, if you simply want to get another call ..... I'd first try one you've tried and liked. And, in default of that opportunity, if you like the GVCC calls, you might get another one, which is set up to be louder.