I hate to say it, but you should have kept the 425. Then the 2520 would be the perfect compliment. In fact, I suggest going back to that. Get a used 425/445/455 and then a heavier tractor for the serious work. And if you want to spend the same kind of money, look elsewhere besides JD, like the Kioti CK20 or CK27 or Bobcat equivalent. The few thousands $ difference will let you buy back a 400 series for the mowing.
I have a CK25/425 combo. Works great, and I won't give up my 425 until I can afford an X749. It's an awesome garden tractor/mower.
Otherwise, best bet is to rent for the big jobs and stay with your 1026r purchase.