I've been wondering the same thing for the last year myself. Mor me, I also have to use a mmm. I like the local JD and Kubota dealers best, so I've narrowed it down to the 4115 and the 7500/2410. I'm trying to stay as small as possible and still be able to use a BH and larger 3 pt implements. At this poin I am leaning towards the JD 4115 (dealer says 4110 has enough power, but I don't want to kick myself down the road) because it has a suspended deck whereas the Kubota's use a rolling deck. Lawn mowing is improtant and my grass is tender under my old maples and my soil is sandy loam so it's real soft. I also like the ability to add a muching kit or use side discharge depending on the time of year (side discharge is great for "raking leaves." I haven't yet seen the 46 backhoe. Looks like more of a pain to move/remove, but I don't concieve needing to change that often. 1/2 hour to put it on is a lot better than not having a BH. I know it makes sense to rent the BH, but I like to have tools available to use at my schedule. I hate having to arrange for everything to be done on a tight schedule. It seems like weather or poor planning or some surprise always makes things take longer than I imagined...
I've heard talk on the Kubota forum that the 7500/2410 are due to be replaced this fall. I'm planning to wait until I can see what changes occur and to see the 46 BH from JD before I make my final decision.
Hope my thoughts help. Frankly, I don't think you would be happy with any of the choices listed. I would just look at your future needs and put that in the equation. For example, I don't want a front snowblower now, but could see getting one down the road. On the smaller series tractors (4115 or 7500) they are about half the price of the next size up tractors (4210.) There is a lot to consider. Kind of makes your head spin.