I'm watching Buffy/Angel for the first time and am part way through season 4/1 so I haven't caught up to the end of the show or started reading the comics.
But I've watched a lot of shows that feature unresolved sexual tension between two characters and have noticed that either the show runners are comfortable letting the characters develop their relationship and let it grow, or they do everything in their power to prevent it and milk the sexual tension for all that it's worth. When I figure out that a show is the second type, I stop watching it. I learned from watching X-Files that it's just frustrating to ship two characters who will never be together. Or the powers that be decide to move them forward, but do it behind the scenes. I want to see the first date and the first sleepover and all the steps they take to the alter and beyond. Instead it's, hey, we had a child together, how did that happen? (X-files, Bones, NCSI, etc.)
From reading about the comics, I get the impression they are stuck in the second mode with respect to Spuffy. I guess, if the plot line is interesting without the romance, it's ok. With Angel and Buffy in two separate comics, though, I can't see them ever getting together unless they decided to merge the comics together. But they would make less money so, I think they'll always be apart, unless they decide to end the comics and then bring them together at the very end.