Andy, you should also consider dirtydeeds' thoughts about the 53" wide flail. It would certainly cover your wheel tracks rather than be an inch shy as the 48" wide flail would be. With a hydrostatic drive tractor you use the engine HP to decide if it meets the flail's HP requirement. You just adjust your forward speed to keep the flails rpm's up to speed. Once you open up an area with the first pass, you can always use less than the full width in thicker/taller/heavier brush or grass if need be.That's great advice. Thanks for the info, and I think I'll go with the Betstco 48". All the other flails also have gone up in price.
My main use for the flail is in my thick woods so I wanted it to be as narrow as reasonable to get between trees, etc. And I can offset it to cover one wheel track while the left side's gearbox barely sticks out past the other wheel. If it was going to be used more in mowing open pasture grass, I would've opted for a wider cut as the B2650 would've had the HP to run it.
If getting through narrow/tight spots with the flail isn't a concern for you the 53" width is something to consider. But....it's only 5" wider, takes up a little more room to store, a little heavier, etc. But still, think about your mowing areas and choose what you think will work the best for you. Either way, you'll be happy. Especially on that new B2601 !!