Right now for my work, IE11 is the new IE. It has spectacularly bad performance issues in its nooks and crannies that slow our web application down by a factor of something like 1000 (it's hard to tell -- but after two days of hacking away inexplicable hotspots, it's running 10x faster and still glacially slow). (Switching to IE10 compatibility mode makes the performance problems disappear.)
Make no mistake, I think IE11 is a huge step in the right direction in terms of standards compliance, but right now it's not really usable.
Make no mistake, I think IE11 is a huge step in the right direction in terms of standards compliance, but right now it's not really usable.