I'm a little late to reply to this post but I have a Wallenstein BX52 that I run on my BX24. It is a beast and while it is pushing the limits of my tractor if used reasonably it works just fine. While it's capacity says 5", personally I have only chipped up to 3" branches but it gobbles them up fine without putting too much load on the tractor. 5" is firewood worthy anyway. This thing weighs in at about 580lbs and has a nice heavy flywheel. The price is not bad especially when its just a couple hundred above the much smaller ones. Wallenstein is a quality unit, great welds and craftsmanship.