Like most have posted already, I don't use a bar addon. I run with as few addons as makes sense, mostly because I don't want to have to rely on fixes to addons after patches to keep playing. If all my addons broke today when I got home, then hardly anything would be different for me. I would definitely miss Jamba and QuestHelper, but can survive without them (just slightly less conveniently).

Bar space can become an issue at times, more so with some classes over others (shaman, mage). I just use macros as efficiently as I can to reduce the number of buttons I actually need. Anything that I almost never use gets put on the secondary action bar, such as tradeskills and situational out-of-combat stuff like all the tracking abilities for a hunter or portals for the mage.