I have one that's similar from TSC - I think it's a County Line. It's great for prospecting before I use the tiller in an area I'm unsure of. It also makes a great stump removal tool for hardwoods up to 6 or 7 inches, provided they don't have Hickory type tap roots.
Since mine doesn't have shear bolt protection I take it slow and wear my seatbelt after almost getting pitched onto the hood the first time I found a big root.
Transport problems with mine was solved (mostly) by pinning the top link in the bottom position on the transmission bracket. This puts the chisel point just a very few inches off the ground, so take it slow on uneven ground. I'm thinking a second mounting point for the top link on the back side of the subsoiler mast would provide an almost horizontal transport position with 12" or so ground clearance.
I picked up a (16"?) middle buster blade that I swap out for trenching and tater duty. The angle is too shallow, so I put a spacer between blade and the rear bolt hole to lift the blade angle up. This worked really well for performance, but beat up the bolt. Need to work out a better angled bolting solution for that application.
-Jim