I've used the Timber Axe, FAE and the Tushogg, as well as, a few rotary mowers and a 20" shear on my hi flow A220 with mixed results. You can make a pretty big mess with any of these attachments. Don't believe the brochures-none of them is going to give you playing card size chips. If you want chips, buy a grapple and carry the stuff to a chipper or, better yeat, burn it.
What are you trying to do? Do you want to clean up slash and grind stumps? Get the Tushogg or Fecon. Are you clearing small diameter brush? Get the Davco or an FAE. It all depends on what kind of look you are trying to achieve.
You can't beat a dozer for clearing ability so I modeled my operation on what the dozer guys do. My 20" hydraulic shear and grapple give me a similar capability to a small dozer with a shear blade and a rake. Shear it, grapple it into burn piles, then go back over the property with a rotary mower to clean up the flags and other little stuff.
Mulchers can do a good job with repeated passes to reduce the stuff but they are painfully slow compared to a D6 or JD650 with a shear blade and rake. Also, these little machines tend to overheat when pushed hard in the woods.
A mulcher will run you $20-25k new and the T-300 with enclosed cab, A/C and high flow is going to be another $48-50k. Throw in another truck, trailer and a toolbox full of spare parts and its easy to blow $85-100k on a skid steer/mulcher head combo with some real limited capabilites. How bad you need to mulch this stuff?
BTW, Yellow Dog taught me everything I know...