Gulf driver,
Here's the rub.
The clutch or shear bolt are there to give way, before binding up the Output shaft/Tranny of your Tractor.
Shear Bolts give way, and have to be replaced every time the blade hits a stump, or the deck gets loaded up and the resistence is enough to shear the bolt.
Shear bolts are pretty much a cheap answer that lacks deeply.
They still may hold torque to your tractors driveline after they have given way long enough to damage your tractor.
It's cheap, and that is why "Budget" impliments use shear bolts.
Spend the extra couple of hundred bucks for quality impliments that have protection of your tractors driveline considered, and protected.
The output shaft/ drive on my own Tractors, have been saved several times by the adjustable clutch on my Woods impliments.
The last time, a Chain from the late 1800's got wrapped up in the Rotovator, with the Tractor spinning at full song.
A quick re-torque after unwrapping the chain from the tines, and it was back in service.
As for a make, I remain convinced.
If it ain't Woods, it's somebody elses problem waiting to happen.
http://www.woodsonline.com/
But then I have local support that would make a Mother cry in Guilt elsewhere.
Go for the Clutch.
Leave the Shear bolts to the "Estate farmers" and yuppies.
50HP is enough load, that the Bolt breaking will be too late to protect the drive line under full load in many circumstanses.
The more power applied, the more the clutch makes sense.
Otherwise,
Repairs will cost the same or more than the CUT, Shear bolts are appropriate for.
75 cent Bolt..... $8,000.00 driveline.
Just sayin'.
Eddinberry