Still using an H, made almost 3000 bales with it last year.  With everything in shape and tuned up right, it has capacity to match any new baler.

Need to keep very good pickup teeth on the outside rows, don't use aftermarket rubber mounted, either steel or factory rubber mounted.  With even one or two flimsy or broken outside teeth, you will hate the baler.

Need good flaps on the bale starter roll ( just 4" baler belting)

keep all belts the same length.

With those three taken care of, it will bale whatever will fit under the hitch, and as fast as you can drive.  

Twine never misses, but is slow being a single twine arm.

Often need to let the indguard float using tarp straps as springs, rather than locking it down with the latch, it can swallow some massive gobs that way.  

Have to be careful starting bales in a single narrow windrow, zig zag very fast.

Very heavily built.

Drill out the tailgate orifice to speed up the tailgate.

start the bale before the tailgate is closed to save a couple of seconds., doesn't need the tailgate until a few inches of bale are made.

I noted last year, that in spite of the single twine arm, I was tieing and back to baling faster than a new JD, he spent so long waiting for the kicker, slow tailgate and baler to start turning again. 

The smooth belts really are easier on leaves.