As for board speed, I can't say anything objectively about that as I honestly prefer the slower speed as opposed to "if someone does not post on the thread within 10 seconds it'll sink into obscurity." fast. Again, this might not be so bad now that the pruning method had been changed to popularity as opposed to absolute age, but at the time it was entirely possible for popular threads with >100 replies and lots of discussion (and even images, wow!) to die after one and a half hours, and board speed caused by meaningless trolling, /a/ blogging, and threads which had absolutely nothing to do with /a/ except for the fact they'd been started with an anime picture contributed to that considerably.
Perfect /a/ in my opinion would be: slightly faster than now, with visual novels and touhou etc allowed (but please, for the love of god, actually talk about something instead of "how do u install ray romano durr" "which path do you think is best lol" or the like) while keeping the pruning methods the same as now.
But /a/ - Anime & Random? No, I think I'll vote for keeping things the way they are if that's the alternative.