I’ve done both.
I 1980 I used a Bruce Random Plank Oak in my dining room and it was great. It is a veneer, but very thick. I installed it over a plywood subfloor and I glued and nailed. Came out great and 24 years later it has not been refinished and it is still beautiful and in good condition. (I saw it the fisrt weekend in Aug.) I have also used prefinished Bruce parquet. Installed it in EX-MIL’s living room in 1979 and according to my daughter, it is still there and in good condition. It hasn’t been refinished either.
The unfinished was installed in a house that I refurbed. We went with unfinished because the floor was so uneven we knew we were going to have to plane off some areas to get it flat. We used solid T&G planks, planed it smooth and used a two coat water based acrylic sealer/finish. I can’t remember the brand but it was easy to apply and looked very nice when completed. We did that in 1995 and, unfortunately, I haven’t seen it since 1997, so I can’t comment on the durability.
If I were going to do it again I would go with the prefinished unless there is an issue like I encountered. Also, the solid plank was much more expensive.