I agree - for the implements and inclusions the B2301 is great buying.
Having said that, a mower in a field can easily bog down with not enough HP. A 60 inch mower in long or damp grass will use all your HP, you'll need to mow slower on the B2301.
I don't think I'd use a belly mower for what you're describing, I think a 3PH mower would be stronger (which you need doing field mowing) and more easily push back under trees without getting branches in your face. It's hard to say without knowing what you layout looks like. Trees in rows without low branches are just fine with a mid-mount, trees with low overhanging branches are much better with a rear mount.
I think I'd be using a bush hog not a mower at all - are you intending to mow weekly and keep it more like a lawn, or are you intending mowing a couple of times a month and mostly knocking the top out of it? Will you be picking up any branches before you mow, and getting rid of obstacles like stumps and stones, or do you want to just mow over them and not worry? Mid mount mowers are limited in space, therefore limited in build/strength. If you regularly mow sticks, stones and stumps with them, they'll break. A bush hog is made to be treated mean every day.
On the backhoe, my father has a mini-excavator on his farm. Brilliant for track work, making burn piles, roughing in drainage. But when he does anything with pipework he gets a hand spade out. I always ask him why, and the answer is that using a backhoe on top of irrigation pipes usually ends up with cuts in your pipes - then you have to fix them. And a backhoe digs a much bigger trench than you need and makes a big mess. A specialised trenching hand shovel is actually pretty quick and makes a nice narrow clean trench. Each to their own, but you may find the backhoe less useful than it initially seems.
I suspect if it was me I'd jump on the B2301 anyway, but just giving a few contra opinions for you to think on.