I have a D928 with the 61" PowerFold deck. I looked at JD's front
mounts, but their price was a lot! higher.
I have some hefty slopes where the property drops down to the
drainage area and back up to the street.
I have the twin-wheel tail-wheels (two wheels per side) and
negotiating slopes has never been a problem (wet or dry).
I REALLY like the front mounted deck; fold it upwards and
you can easily clean under the deck; change blades; and so forth.
A really nice feature of Grasshopper's front mounts is the
ability to use different implements on the front.
At this time, the deck is stored away and the rotary broom is
mounted. I used to use the JD 4115 FEL which I later traded in for
a 3520 w/ FEL.
My son has to pull his car out of the garage so we can get the grasshopper
out. By the time he's backed out; wait for the Grasshopper to get out;
and then pull back it - the 67' driveway portion is almost done -
the first pass on one side is completed and I've almost completed doing
the second pass (on the other side of the driveway). AND snow
is cleared away to the pavement - unlike using the FEL.
My youngest managed a LCO and he 'ragged' about how he didn't like
the Grasshopper's rear sticky out so far - compared to a SCAG ZTR.
But after using the Grasshopper this season; seeing how handy the
fold-up deck is; and how quickly and cleanly it clears snow -
he told me I made a darn good decision buying the Grasshopper.
I wish the Grasshopper diesel was a YANMAR direct injection vs.
KUBOTA's indirect injection diesel. But, it's runs great and starts
even when it's colder than....
Now, the 3520 sits in the garage waiting for the BIG snow to
hit or the really wet/heavy stuff to fall; otherwise, it's a job
for the Grasshopper.
And I'm definitely a JD man! But, the Grasshopper is awfully
handy.
Merry Christmas,
Lon
(I tried hiding in the corners but the cursor keeps creeping out. 
