My needs are very similar to yours. I have a subdivision, maintaining ~45 acres of lots and my adjoining 15-20 acres that I mow. I had been using a Kioti CK30 4x4 with shuttle shift. This machine would only handle my 5' Rhino rotary cutter. I had this tractor of 4 years, and it was bulletproof, might take a look at Kioti. My problem it was taking 30 hours to mow all of the lots and yard. Ended up buying a 09 JD 4320 with cab, 48 hp, roughly 44 hp at pto. I have had to two weeks, put about 30 hours on it. Great tractor, now mowing with Woods RM990 finish mower. 90" cut with stump jumpers on spindles and blades swivel like on a brush hog blaes, really works like a combination light duty brush hog and finish mower. I cut 5 acres this AM at 6 mph and looks like a golf course, when went to rough field and cut another 3 acres. The grass had not been cut for 4 months, had to raise RM to 5 inches but rough cut good. You have got to look at this mower before you buy.. 4320 on rare occasion pulled down maybe 500 rpm but there were clumps of thick grass 2 feet tall. I believe you can buy 4320 hydro 4x4 with Cx400loader for ~$36K. I believe a 4520 will cost a two g' more. Sweet tractor. I wouldn't buy anything smaller than a 48 hp. Also, after having both shuttle shift and hydro, I'd never go back to shuttle shift. Mowing foward and backwards to cut clean corners and loader work is now easy with the hydro.
If you don't mind my asking, how much did you pay for the Woods RM 990? The leading mowers that I am looking at are the Woods RD 8400 and the Taylor Pittsburgh 3184. I don't have all that much area to bush hog so this may be a good compromise as long as the grass still looks nice like a regular mower and not like a regular bush hog. The biggest reason for me wanting to get a used bush hog was for me to knock down the area now as it hasn't been cut in a year and then mow most of it with a finish mower. If I could get this combo unit and cut the very small area that I wouldn't want to put a normal finish mower on and pay less than a new mower and used bush hog then that may be the way to go. I can do a little hand trimming with a blade on my Stihl trimmer to get things started if need be as well.
As for the JD 4320, it is a very nice tractor and I like it very much. My problem is that I just don't like it so much more than the MF, NH or Kubota to pay that much more for it. Plus all the JD dealers have been bought out by a big dealership so there isn't much competition and I don't think they'll go down to $35,000 for a 4320 Cab with 400X loader, which is probably my max. Plus the biggest reason why the MF and NH are in the lead right now is the 72 month 0% apr financing, vs. JD's 0% apr for 60 months, which is all Kubota is offering as well. At least with the Kubota I can pick up a 4240 HSTC with 854 loader for about $33K. So, I may have another try at the JD dealer with the 4320, but right now it looks like I'll be driving a red or blue tractor.