What do you have them converted to?
I have one at 720nm, and because I liked the colour, I had one converted to 590nm.
I have three, but since I got my Sony A7 done, I haven't used the other two. I did the A7 to get into the mirrorless thing, which assures good focus and full frame to boot. It's at 590nm but I have a few filters that fit the lens I'm using, so I go to 720nm and even 830nm on occasion...you can stack on your 590 with filters and not need another body!