New member here but a long time lurker while researching (haven't introduced myself yet, but will shortly). Just wanted to chime in as I recently purchased a new 3032e with the Frontier GM3072 finish mower. I have no complaints at all about the mower, it leaves a great cut, same or better than my traded in zero-turn, albeit not quite as fast understandably. It also cut a couple neglected fields very well that I thought I may need to use a bush hog on. I just raised it up and it went through it no problem without bogging down at all (I know the fields well, no stumps or rocks or anything to hit, just knee high field grass). My previous 60" Hustler Fastrak bogged down pretty good in it.
Something else to consider is if you have a quick hitch that you'll be using it on. If you do, you'll either need to modify the mower so that it floats properly, or buy the quick hitch conversion kit for the mower. I was lucky in that when they delivered the tractor and mower (no iMatch or conversion kit, I didn't buy when purchasing), there was a small leak right under the loader controls noticed fairly quickly. They picked it back up the next day to fix and the salesman threw in the iMatch and mower conversion kit for free for the hassle, had them both installed before bringing it back to me. I believe the conversion kit for the mower through Deere/Frontier is around $225 or so.
Link to Frontier mower conversion kits:
iMatch™ quick-hitch conversion kits for grooming mowers
Lastly, the Frontier mowers don't come with an anti-scalp roller unless the dealer adds one on, at least the ones I looked at didn't. I figured out real quickly after mowing with it the first time that I needed it even though the salesman said I probably wouldn't. My yards are pretty flat with slight raises. If I ran the mower over one of those slight raises that the casters straddled, the deck would scalp the ground. The first time it happened it looked like I had a fresh piece of sod laying on top of the mower and a nice brown patch in the yard. I ordered the anti scalp roller kit real quick after that and put it on, no more scalping. The roller kit was $98 through JD.
The salesman suggested I go with the GM3072 due to the heavier duty deck compared to the GM1072E (8 gauge as opposed to 11 gauge), not to mention he had some 2017 new mowers still on the lot that he was able to discount to within about $150 of the price of the GM1072E. I didn't price the GM1072R, so not sure where it would fall in this, but it appears to have the same gauge deck as the GM3072.
Also FYI, Deere only sells Frontier brand mowers.
Just some thoughts!