I think that we are all getting tired of the limits of SMF.
I think SMF works pretty well now. I fixed the most pressing issues. (This is one of the reasons I haven't been too motivated to get this job done.)
I agree with you that it *works* well, however it's really a 2005 software.
No ayax, no mobile style, it dosen't detect properly readed and udreaded posts (at least for me it dosen't send me to the first unreaded post), it dosen't has any kind of notification system, etc.
For me they are all shortcomings, it would be really great if you yourself upgraded for (my personal preference) xenforo. You should be able to integrate the features that this board has and will be missing there in a week of work or so.
But unfortunatelly i understand if you follow the old "if it isnt broke, dont fix it" motto, i'm a lazy person and i follow that too on my work online.