it really is easy to use and I like the design very much. However it is really slow on my computer. Tried it under chrome and firefox but editing an area with more than e.g. 15 buildings it gets really unusable. The CPU-usage goes up to 100%. I’m wondering why this problem (and I have a quite fast computer) (nearly) isn’t adressed at all those news about the iD editor…
I hope that it gets faster in the future and that this problem is not caused and / or limited by HTML5 and JavaScript :(