If a character evokes strong feelings, the character is successful. You have gotten your readers to care, even if their desire is to claw him or her to bloody gobbets. Even better if the reader reaction is the one you wished to bring about.
A character that invokes strong feelings is a gold star. Whether those feelings are of hatred, love, respect or whatever, it shows that you've touched the reader and gotten his or her attention. You have had two people come away from your novel with strong feelings regarding your character. That's a positive. Good luck!
Strong feelings are great - the problem I see is the fellow who wouldn't finish the book. I'm not sure that's quite so great, since one would hope (at least I would) for word of mouth recommendations. Hating a character is one thing; despising the book because of it is quite another. I would try to get a bit more feedback on this character (from other people), especially since you received such diametrically opposed responses.
I like to think if I learned something from a character I'm reading, it was a successful portrayal. If I can relate in some way, I think the character becomes real. Written people should be consistently imperfect for me to feel like I've met them at the end of the read.
Characters that invoke strong feelings from a reader, good or bad feelings is always a great thing, it's like your character is an actual person because no everyone is going to love the character, there will be people who hate them. If you got two opinions completely opposite from each other, I think you've done a great job
A character like that is gold, and it is just because he is a conversation starter. Look at bands like Nickleback; bands like that have more haters than lovers, but glance at their record sales and you see why they aren't depressed.
