For almost all of the formal training I have taken, I used either my Kimber 1911 or my Glock 26. Much of the time I chose the Glock because I had not yet acquired the Kimber.
My usual thinking is to use a gun that gives me no excuses for poor performance when I am paying for the instructor's time, and I have a lifetime to transfer those skills to whatever gun I might be carrying at the time. Occasionally, I brought the Glock 26 to class instead, and found that my performance did not deteriorate too much with the more difficult gun.
On one occasion, I brought my Kel-Tec P-32, drawing from both pocket and ankle holsters. It was hardly the best way to learn pistol shooting in general, but was an excellent way to quantify the capabilities and limitations of the gun and carry methods.
Bring both the Rohrbaugh and a larger gun.