For what my input is worth... I have both versions. A 2006
BX24 which is the 50 series tractor and a 2013
BX25D (the 70 Series).
The
BX25D does indeed roll on when the pedal is released. I found that to be rather disconcerting when I had it at my home where there are many obstacles and some rather steep drop-offs. I find it somewhat clumsy to use the left brake. I moved it to the shop property where there are fewer obstacles. I have become more accustomed to the additional roll and find I just need to anticipate it a bit. I still scramble for the brake occasionally and have come very close to bumping into several things.
The
BX24 stops quite quickly. I don't find the quicker stop to be particularly objectionable, even when stopping in reverse. I find the quicker stop to be better for my use in the tighter areas at home. Occasionally it gives me a bit of a jolt, but mostly is just quick and relatively smooth. It could be that it's my particular tractor, or I've just gotten accustomed to the control. The brake on the right is definitely more comfortable for me, as it is the same as all my vehicles and is instinctive.
I should add that in addition to many other projects, I mow with both tractors. I mow aggressively. Full throttle, high range, and in open areas, speed full out. I find both the 54" and the 60" deck (I have one of each) to do an excellent job.
Because of some of the rather vociferous complaints about the abrupt stop in reverse, I did some research a few years ago. There appeared to be no internal changes to the transmission. The only differences I could find that would affect the infamous "sudden stop", were the pedal linkage and the damper. The 50 Series damper only slowed the pedal return in one direction; from forward to neutral. The 70 Series damper, retards in both directions, forward to neutral and reverse to neutral. There were changes to the linkage as well. I suspect this extra damping is what causes the roll on. The tendency to "roll on" is probably greater at cold temperatures as the fluid in the damper is probably more viscous when cold.
There are a few things I prefer on each the older and the newer tractor, but nothing major in either case. I really enjoy both tractors and don't really have a favorite. Any version of the BX is a great, reliable machine with far more capabilities than one would expect.
Enjoy your machine and have a very Happy New Year!
Harry