Flail, flail, flail.
I use a 10 foot Vrisimo behind my Kubota 7060.
If the grass is fairly short to start with then the cut is about 85% as good as a finish mower, and it cuts a 10 foot swath faster than my zero turn can.
If it's long, it's three times as good as a brush hog, mainly because it distributes the cuttings evenly so they disappear much more quickly.
As a previous poster said, it's not so much the cut with long grass that matters, it's how the cuttings are distributed and how chopped they are. No way to have a finish look cutting infrequently unless you pick up (e.g. hay) all the cuttings. The closest you can get, in my opinion, is with a flail.
I suspect I may have one of very few Vrisimo flails on the east coast, but I've been super pleased. Figure about $1k per foot of width on the Super Series if purchasing new.
I love my flail. Look up any postings by flail master Leonz for info.