Regardless of whether the iguana is green or has horns, it's demeanor will depend alot on the effort you put into it. I currenly own 7 Rhinos and am caring for many Greens. In my own personal experience my Rhinos seem to enjoy human interaction more than the Greens. In most cases the Greens appear to tolerate handling and affection where some of my Rhinos will actually seek out attention. The gender doesn't seem to be a factor.
Here are a couple of points that may help in your decision. Rhino Iguanas can live longer than 50 years. Obtaining one is basically a lifelong committment. Male Rhinos can weigh as much as 30 pounds as adults. That's a lot of lizard to deal with if you've not put in the time and effort to socialized it well. Rhinos are terrestrial animals and require a lot of ground space as adults (altho mine enjoy basking spots above the ground). The Rhinos seem much hardier, healthwise, than the Greens and can tolerate minor mistakes in husbandry with no ill effects. Mine have proven to be less prone to infections and they heal quickly from injuries.
A Rhino bite is not something that should be taken lightly. I'm glad to say that I've never been bitten except for the occasional nip while handfeeding. These are photos of my 3 year old male Rhino after a 5 year old female got tired of his advances and decided to retaliate. The jaw was broken and flayed wide open. His jaw was wired back together and the wounds stitched up. The photos are immediately after surgery and then one week later.
You can barely see the twisted ends of the wire in this one, near the 3rd stitch down.

