I picked up the 925 at the dealer early this morning. It has rained for the past couple of days and it was very wet this morning. Had a lot of growth on the first property (about 2 acres of a variety of grasses). I put the deck into discharge mode and at a height of 2.5 inches. Does a good job of discharging the wet grass, however, like most (if not all) decks, a lot of the grass collects on the top & sides of the cutting chambers. When I finished, I scraped out around 5 gallons of wet, clumped grass.
Moved on to the second property which is about 4.5 acres of nice bermuda which I mow every week. Used the deck in side discharge, but would change to mulch, now and again to mulch up some leaves, etc. One thing I noted was that when changing from mulch to side discharge a clump of material would get shot out from the chute because it had collected against the close-off plate. Another thing I noted is that JD uses a high-lift blade on the MOD deck.
Hope this helps! Will continue to use the mower until the dealer threatens to send the law after me!!! Really do like the mower!!! The 900 series hydros are just fantastic, and it handles so much better than my 830.