Just curious, but how bad of a job does your tractor (7510???) do cutting grass? Not much of a difference in weight. Bx has better manuverbility though. Maybe you have to compile the differences of the two machines and decide if its worth it. I wouldnt call it a down grade. Every machine has their purpose that they were built for. The bx is extremely easy for anyone to use. We ALL know a bx will do what you need, but the question is a couple grand worth the switch.
As I was corrected, I meant downsize. This whole downsizing thing started over five years ago when I found the B's ground contact mower didn't provide much forgiveness on my "bumpier" lawn, but moreover, the front turf tires cut circles around all my trees regardless of what I did to prevent it. I tried different tires, but neither worked.
Now, I have a son who will be mowing next year, and I started looking for a dedicated mower, but after seeing what they go for used, I could wrap it all into a BX for minimally more, and have one great tractor for all needs with basically compromising ground clearance, which I don't need anyway. Then , cut the maintenance costs and storage loss from another machine, and the scale tips farther.
Visibility and comfort alone are a couple major incentives for my wife and son to use the BX. Although I doubt she'll ever rush out to mow with the BX, my wife sat on one tonight and agreed the BX was more comfortable than my B, but the comfort is the "feeling" she gets sitting on it, not the seat cushion. She could see around the BX because it sat lower and the loader subframe wasn't blocking her view of the "road" like the ones on my B.
I mow 75%, remove snow 10%, and use the FEL for the last 15%. Certainly the BX has more than enough capability for my needs. I am banking on the BX being easier on my lawn, providing a better lawn cut because of the suspended deck, being easier to maneuver around the yard, being easier to maintain (the deck is much easier to remove than the B), being more adequately sized to my needs and yard (as well as the in-laws yard in town), and being a better choice for the son when he starts mowing soon (and the wife, if she does as well).