Interestingly enough, even after so many years flying pointy-nose kerosene burners, I find enormous joy in putting around in GA airplanes.
Lately I've been flying around with
@uncreative in a 172 doing basic instrument stuff and it has been an absolute blast.
I've said this before on JC (and it received a notably bad reception), but I think 121 companies should also own a fleet of Decathlons and make their Captains have a monthly currency to go fly acro and get tailwheel landings. I'm still amazed that we have airline pilots out there who've never been upside-down in an airplane, and I think the automation-induced atrophy of stick-and-rudder airmanship (see Air France 447, et al) would be well countered by horsing a taildragger around the pattern.
Failing that, I think it is the professional responsibility of pilots who carry pax for a living to make their airmanship experience bucket as deep as possible. That means they should be out doing non-121 flying in the most non-121 types possible: gliders, acro, seaplanes, etc.
If I remember right, the answer I received from the JC 121 crowd was something to the effect of, "if my airline wanted me to have that kind of experience, they'd include it in my training."
Because, after all, no pilot has ever had to deal with a situation that wasn't covered in formal training.