I could do without the colored text, as some of it is still hard to read. I really prefer the black text on white background, as it's least stress on the eyes to read...but I would at least like to be able to not have to read fluorescent blue on gray gradient background.
I also liked being able to see the log and the summary (kills, deaths, current goal, etc) on the same screen. now I find I end up swapping back and forth a lot to get the information i used to be able to get at a glance. But it also depends what i'm doing. running heroics, I don't care much about the kills/goals. running quests, when it sits there and does nothing, I find myself scanning the logs to see what it's doing...or if my character dies a lot, i'm trying to see what it's doing. etc.
The settings are too complicated, too many pop-ups. Though once set up, it's mostly not changed. maybe give "closer" (as in, less clicks to get to) options for some of the most commonly used settings. toggle profession gathering and looting. Those are the ones I seem to change the most.
I would like to have easier access to plugins. I toggle allrounder, profession buddy, rarekiller, etc a lot during a botting session, and it's a pain to have to go through that many clicks.
Not sure if it's still happening with the latest version of HB, but with 4620, even if I disabled certain plugins, HB would continue to use them until it was restarted. Mostly the issue was with equipme as far as I remember, but there may have been some others, as well.
finally, i would like the gui to remember the size I last left it at. while some people like the new sleek and small look..i got dual monitors and have absolutely no issue with space for my HB window. in fact, i tend to make it larger, just so I can read more than 2 lines of a log at a time. Not a major thing, but it would be nice if it stayed that size once I change it.