I like Ivan (pr. EE-van), but it's been very popular here so I'd never use it. Ivor (pr. EE-vor) I really hate for some reason, even though I know Ivors who are very nice.
I've never liked Ivan, much as I love other Russian names.Ivor, now there's an intriguing name. I'm never sure, though, if I'm supposed to pronounce it "EE-vor" or "EYE-vor." I'd love to see it get more attention and use.