I have always been inclined towards geared transmissions because hydros rob a noticeable amount of power. This was very obvious to me about 12 years ago when shopping for a small mower/tractor -- the geared model was like a hot rod, while the hydro model felt like it was running on molasses, and was just pathetic. So I bought geared then, and that tractor continues to serve me well for mowing and lawn maintenance.
I did a fair amount of work on a JD 3005 over the summer/fall of 2011 cleaning up from Hurricane Irene, and the geared transmission/clutch combo worked fine for everything we did. To me, it confirmed my preference for geared.
However, when shopping for a new tractor for myself recently, I went hydro because it seemed like a better choice for what I wanted to do -- a lot of front loader work, landscaping, some tree work, and some light logging/skidding in tight quarters in the woods. Those things either require a lot of fwd/reverse motions, or very gentle controlled creeping, or both. After having used the tractor for a couple months, I am glad I went with HST this time around and think I made the right choice.
In this case, I consciously went for a higher horsepower tractor to offset some of the power loss of the HST, jumping from a 26HP
B2620 to a 29HP
B2920 (the tractors are otherwise identical). It seemed a little odd to pay another $700 just for 3HP, but to me that was the best way to get an HST and offset one of the known downsides.