I did my review on my new JD 925 already where I mentioned a little bit about the MOD deck. But I've wanted to do a review specifically for the MOD deck because when I was looking at buying my mower, I couldn't find much info on the MOD decks. So when I bought mine, I went by what my dealer told me (who I trust very much). This will be in regards to a 54" 7ironPRO MOD deck on a 2010 JD Z925A with 27hp engine. For those of you who don't know exactly what the mulch-on-demand deck is, it is a mowing deck offered on John Deere commercial ztr's. This deck allows the operator to switch from side discharging to mulching with the move of a lever. It has baffles underneath the deck that move to allow the deck to be a fully chambered mulching deck or a complete discharge deck. This deck can also be used with the JD bagging system without any problems. The discharge performance of this deck is actually quite good. I can throw clippings upto 3 passes away, which would be roughly 12 feet away. It disperses the clippings very evenly as well. I can cut several inches off of a lawn without having to double cut and still leave the lawn looking good. The mulching performance of this deck is actually quite nice. I didn't really know what to expect since I didn't have any experience with this deck. It works the best when maintaining weekly accounts and cutting 3" or less off, otherwise you would have to discharge. If you do cut 3" or more off while mulching, you will notice a windrow of clippings on the discharge side, its not bad but can be noticable in more thick/lush grass. With the spring rain that we've been getting, grass has been growing like crazy so it has really put this deck to the test. I really like it for when I have to double cut a lawn, I will discharge on the first pass and then mulch on the second and you can't tell that the lawn wasn't bagged. Compared to typical double cutting where you are discharging both passes, the discharge then mulch method is 10x better. It looks so much cleaner as there is very little grass left on top of the grass but rather most of it is mulched in. I love the fact that I'm able to use the bagging system on the mower without doing any major modifications. Once the brackets are in place there really isn't much to do. The only thing you need to do is take off an extension plate on the discharge blocker and put on the bagging unit. I can switch from mulching/discharging to bagging within 2-3 minutes. A big plus with this deck is that when you are bagging, you can choose to have the discharge fully opened or halfway closed. By having the discharge halfway closed while bagging, you will collect a fraction of the grass you would when fully bagging. When I bag with the discharge closed halfway, I collect about 1/4 of the clippings I normally would, which is awesome. As long as the grass isn't too long, the lawn will look just like it was fully bagged, but really you are mulching most of the grass you cut. When the lawn is longer, you will have to fully collect, otherwise you will get clumps left in the lawn. The construction of this deck is just like the standard 7ironPro decks. They are built quite tough, plenty of reinforcements around the deck and of course the 7-gauge steel they use is quite tough. It does have a few more baffles underneath the deck which make for more spots where grass can collect. However, it is still a pretty smooth underside of the deck and grass really doesn't build up too bad under there. This is one great deck, I've been very pleased. The MOD feature can actually be used more like an OCDC if the operator wants, but it will leave much better results than an OCDC on a standard deck. The MOD deck does add almost $1000 onto the price of a mower, but I think it is well worth it. It can do everything any other deck can but with the added benefits of a mulching deck. I do have one thing that I annoys me...that is when I am bagging. The deck has enough air coming out of the front of the deck that some loose debris on the lawn (leaves or thatch) can get blown around by the air coming out of the front of the deck. Its not bad, but is just a little annoying. But that is the only complaint that I have with this deck, but I think it has something to do with the raised front edge of the deck which is on all decks MOD or not. Hopefully this review will be able to help someone who is looking at buying a John Deere mower. If you have any questions feel free to ask and I'll do my best to answer them. If anyone else has a 7ironPRO MOD deck, feel free to put up a review of the deck and what you think of it.