So I went a little wild with the WGS speaker sale last fall/winter. One of the speakers I got was a G10A. I built a Mojotone Princeton Reverb this spring and the G10A sounds great with this amp.
But, just for kicks, I decided to try a bunch of other speakers with the Princeton. I liked the 10" Veteran almost as well as the G10A. Different tone but very nice. I tried a G12Q in a 1 x 12 Extension cab (alone not in combo with the G10A). Not so good. Reaper 55hz, again, not so good. Black & Blue was great but probably a little too underpowered for the the amp.
Finally, I tried a G12C/S. It sounds really good alone. But, there was some magic that happened when I tried it in combo with the G10A. I think the extension cab is destined to accompany the Princeton forever!