Hey Votum,
I'm sure you conducted a search history on here before you asked your question. I am a Grillo dealer and also work on BCS machines.
Biggest difference between BCS and Grillo is brand recognition. BCS has been sold in the US for nearly 40 years (under "Mainline" the first 5 or so years). Grillo has been imported for 7 years. They are very similar machines with similar features. The Grillo is gonna be a better bang for the buck as there are less middlemen. You'll pay far less for an 85d that will do everything a 732 will do, and you'll have many more attachment options than the average BCS dealer offers. Frankly, neither BCS nor Grillo make a lot of attachments on their own. Rotary plows and flail mowers are made by Berta, chippers and sweepers are made by Caravaggi, many of the rough cut mowers are made by Del Morino or Zanon, all the mechanical unpowered tools are made by Aldo Biagioli and Figli. You're not gonna get anything that BCS hasn't bought and painted blue from the huge majority of BCS dealers.
The Berta flail mower is head and shoulders above BCS's flail mower. It has a much more robust rotor with more and stronger hammers, a better height control system, and a removable baffle to let material pass through for a courser chop when you want to mow but not grind up the material ultra fine. Their rotary plow is unbelievable. I'm amazed every time I mount it to my 850. Words can't describe how good a job it does. In my soil, it tends to burn through points. I get about 4 hours run time on each corner - 4 corners, about 16 hours per set. Its nothing to change them - two bolts per point times four points.
Forget about the 732, it's overpriced for the features it offers and is no good for a lot of mowing as it is missing steering brakes and a third working speed. As I mentioned earlier, you can buy an 85d for $600 less and even a 107d for $200 less. The 107d has all the features of an 853, but has slightly smaller engine options. It'll run anything a 732 will run and it comes with the third working speed and steering brakes.
Grillo has the edge in soil working. They started out as a tiller company in the 1950s and gave BCS their tiller technology while the companies worked together for a while in the late 60's, 70's and early 80's. Today, the Grillo tiller is far superior to the BCS tiller. BCS is building essentially the same tiller they were making in 1982. They've done a few things - beefed it up a bit with heavier shafts, made the height control external, and they did upgrade it with a round hood and their 3 dog PTO in 1994, but it ain't much different than their 1982 model. On the bad side, they took away a width option and made changing tines a real PITA. The Grillo has Bolo tines in a helical pattern, one handed depth control, a more robust yet narrower profile gearbox, 5 width options, and a design that makes tines easier to replace.
The root digger plow is a good tool, BUT you need two things - clearance and traction. Plan on mounting 12 inch tires, 5 or 10 inch axle extensions, and about 100 lbs of weight per tire. For right now, this is your best bet for digging root crops with a two wheel tractor. I've seen some chain diggers and vibratory diggers in pictures or videos, but do not know of any for sale in the US. If there is a source, I guarantee you'll need something bigger than a 732, 85d, 107d, or 853 to run it. I'd bet you're gonna need something like a G131.
Good luck with your decision. Don't forget to report back on what you do. Too many fellows come on here, get advice, and don't bother to come back to follow-up.
