And why is the 38G not in this discussion? Looks the best and turns the nicest

As for the J v L. As a 38G driver I can get in the J and feel fairly decent about it. I tend to have more trouble with the L because of the power assisted ailerons .
Interestingly enough I came across a mention in a WW2 38 history where the guys transitioning from the early 38s and the early J to the J-25 and L with the power assist took a while to get used to it because it was more sensitive on the controls.
Pick one, stick with it til you are comfortable and enjoy. It's not a bird that folks get decent in after only a few flights, and, at least in my case, a great night where it's all working, is usually followed by a night or two where I'd swear I'd never been in a cartoon 38 before.