My advice is to stay with the rental ex as opposed to a tradein on a
BX25, especially since your 2660 is likely paid off.
A miniex will dig circles around a BX, especially when trenching.. Getting off the seat, moving forward, then resetting the seat takes a huge amount of time (the BX seat system is pretty pathetic, if it was a rotation style like on larger machines it would be 100x better) Plus with its tracks, a mini is better in soft ground.
Once youre off the lawn the BX is basically useless because of its low ground clearance and high ground pressure. I cant even crawl over a shallow ditch without bottoming out on the hoe or someother part like the front axle. The hoe on the BX is strong for its size, but weak in actuality when compared to a mini or even a slightly larger tractor. Its short length and strength means you cant lift the back end of a BX across a trench to get off it (if you are unable to just drive away forward). Usually what happens is you an swing the back end over, but one tire ends up right in the middle of the dug out area, meaning you have to put a plank under to get it over.
Another advantage of renting a mini is you can use the BX to tow a dump trailer to move spoils around. Any serious stumps say 12" up, will take a long time with a BX. It can be done, but if you have any amount to do it will take forever.
If youre dead set on trading in, consider a B at minimum, an L would be better, mostly for the increased ground clearance and strength. BX are great mowers and powered wheelbarrows for their size, but when it comes to digging with the hoe they come up short (unless youre willing to invest lots of time to do the job). If youre used to what a miniex can do, you will be very disappointed in the production with a BX, even if your time is unlimited, the limits with the BX will be quite frustrating, the only advantage is you can do things at your own pace as opposed to planning out a weekends worth of work for the rental.
Another thing is once your done all your digging projects, the BX hoe will just end up sitting around 90% of the time. And now with my Zero Turn, I dont even need the BX to mow.
I say this as a BX owner who wishes he put the money spent on the BX hoe towards an L, without a Hoe and just continued renting the mini when needed. A larger tractor would be more beneficial to me day in and day out (for things like moving firewood, box blade work, bushhogging etc) over my now-hardly-used hoe.