I love Nui but I've had quite a few problems with it.
First would be that the majority of the time I log into the game nothing shows up except for recount in the middle of my screen. No party frams or action bars or chat logs, nothing. So I have to /nui rl to get them to all work again.
Second, when using a vehicle, whenever I dismount my action bar no longer works when hitting the corresponding number button. I again have to dismount and then /nui rl in order to get them to work again.
Third, when I'm on my druid and shift into a form(cat, bear, or tree... boomkin has a different set of problems) and then shift back to caster form and try to push the numbers that are on my action bar it will try to use the action from whatever form I was just in. EX when I am in cat form and shift back to caster form and hit "3" for my moonfire it will say that I don't have enough combo points for that move or if I hit my number 2 to cast wrath it will say I need to be in cat form to do that.
Forth, when I switch into moonkin form the new action bar that will come up will be the same action bar as the lower left and lower right action bars not a new one like all the other forms have. And I can't swith the actions on it without it changing the bottom left/right action bars that none of the other froms are messing with.
Last, and most annoying, if ever I'm in a party and need to /nui rl becuase I just dismounted or my action bars are responding, then when it reloads all my party frames are gone and I can't get them back unless I leave the party and then /nui rl again but I can't do that becuase my player protrait is missing so I can't right click it leave the party so I either have to wait for everyone in the party to leave so it disbands or I have to log out and back in again.
I have tried disabling all add-ons except nui and I deleted my WTF folder and neither of those seems to be working.
I love the set up and how you can move things around. I would move the map from out of the middle of the screen as it's right were I look most of the time and most of the time I don't need to be looking at my map. Also I wish there were an easier way to target people when they are on mounts and see the vehicle's health and not the players but I get the feeling that's a blizzard's interface problems as many mods have that problem.