Thought I would report on some further experiences with my 72" belly mower.
1. Drive over technique. I have been doing this and it works great. I bought two metal automobile wheel chocks that have traction grips on them. I use them as a "ramp" for the front wheels--what Mike uses the wood blocks for. First, while the deck is on the tractor, I turn the wheels sideways, then I lower the deck onto soft ground. Put the chock-ramps in place. I dont even lower the gauge wheels. (I cut at 2 1/2", so that is almost to the bottom anyway.) Put the tractor in 4wd and it drives right over. I dont see any greater potential for damaging the deck than when the gauge wheels are an inch lower, because the deck is still not touching the ground then either. This is definitely as fast as a 3ph mount, but not faster than a Freedom Hitch mount.
2. Deck pin up. I have had great difficulty inserting the bent clevis pins to hold the hitch arms up, and even greater difficulty in inserting the hairpin in the clevis. I bought two 6" long. half inch hitch pins with a handle on the end to use instead of the clevis pins. They insert and remove easier because they are much longer and have a handle and also because they are tapered at the tip. The hairpin is still an impossibility, but I am working on a simple chain or string that can loop through the hitch pin handle and keep the hitch pin from falling out.
3. "Suspending" the deck. The gauge wheels of this ground contact deck can rut the very soft soil near my creek. I experimented today with simply raising the deck wheels about an inch off the ground with the position control and leaving it in that suspended position. (I have to mow higher here anyway because of roots and small cut stumps.) This worked very well. No ruts and an excellent cut.
4. Irregular wheel heights. My garage floor is the only thing I have that should be level. When I drop the deck, all the wheels are on the ground except the front right wheel, which is about 1/2" off the ground. I don't know what to do about this.
5. Deck of the year award. I have been looking at 30-40 hp tractors recently and I feel I am pretty familiar with all the 60" and 72" belly decks from Kubota (from the BX up) and from JD. I would say that the 2710/2910 72" deck is overall the best of the lot. There are none easier to remove and install. Nothing is simpler than the 3 spring pins on the 27/2910 72" deck, and you cant drive over the JD's. There are no decks easier to maneuver when on the ground because of the 4 rotating gauge wheels. Even though a 60" deck is smaller and lighter, the lack of 4 rotating wheels make all of them overall less maneuverable when on the ground. And, of course, the 72" width is superior to a 60" width for all purposes in my book.