IMHO a subframe should be mandatory. You can and will throw the tractor around if you are as enthusiastic as myself when it comes to using the BH. I just can't believe the 3PH can stand up for very long with the possible forces generated by a BH. A 3PH may suffice for digging bushes out of the front lawn but used hard it will show it sooner than the sub frame model. Now, there are trade off's you do need to consider, like the MMM might not be compatible with the sub frame so think ahead and ask plenty of questions.
You should always consider the competition for a purchase as large as a BH. Don't be swayed by any talk of warranty issues with a non OEM BH on any tractor, just know what is covered and what is not and for how long and have it in writing. It may be beneficial to get the BH from the dealer you bought the tractor from but don't be pushed into any one brand. Do your home work, try to use any one you consider for at least a half hour and keep in mind the tractor hydraulics will likely make a difference so compare apples to apples if at all possible.
I can't believe you could be any worse off with an off brand. I'm not overly impressed by my BH, strong but short lived. CHEAP cylinders. I thought it was the cat's meow using it at home for what I considered to be sizeable projects. A couple of days hard work took it's toll though. It lasted about 140 +/- hours and I had to re-seal the cylinders due to piston seal failure. By the calendar the warranty had expired but 140 hours? I call that infant mortality. Here's an idea, ask for the price of a cylinder re-seal out of warranty, it's a sobering number and you are dead on the job if you don't go for it. Another idea would be to survey all TBN members as to what items on their various BH's have needed a bit of fixing. I don't mean to imply that any one BH is longer lived than any other given equal use, I only suggest you keep your eye's open and consider everything.
Don't expect the garden variety BH to perform and last as long as the commercial type.
Back to your original question...yes.
All the best and pic's are appreciated when you decide.
Martin