I ran a 3 pt. 5 foot Bush Hog rear discharge finish mower behind my JD750 MFWD (17 pto HP) after retiring the mid mount mower. I wish I would never have bought the mid mount mower from the start.
Now.... behind the Kubota B2650.... I run a 6 foot Bush Hog rear discharge finish mower. It does a mighty fine job in my opinion. I mow around a number of trees, house, outbuildings, etc. and you quickly develop a mowing pattern that eases the technique around the trees or other obstacles. It's my dedicated mower.
As
@Bearcatrp mentioned.... you do need to pay attention to the rear "swing" until you have your mowing pattern figured out.
I'm frequently changing between rear attachments: mower, cultivator, rototiller, backhoe, etc. and love the ease of hookup/removal of the 3 pt mower in order to change between the various implements. The older belly mower under the former JD750 was a royal pain to install/remove!!