round baler suggestion

I'm looking for a round baler that can be run with a 35 - 40 hp tractor on fairly level ground. I've heard and read the JD335, NH 630, Hesston 530 and 540, and some m&w's and vermeers can be run with low hp. I'd like to stay in the 4k to 5k range. I'm only looking at around 40 acres a year so speed isn't a huge deal right now? Can y'all give me the pros and cons on these or any other suggestions?

round baler suggestion