I could only have delivered half of what I've done over the past 5+ years if I had to use something other than Ext JS. I chose it mainly for the superior grid and its excellent data package, which are still at the top of their game today. I don't know why something like setting focus eluded you so much, so perhaps something else was going on and getting in the way (I've painted myself into a corner countless times and wanted to blame the framework, but in most cases, it turned out to be my own fault). And as for workarounds, occasionally you might need to put one in place to solve a bug ahead of the next release, but that's not often (no framework is immune to the odd bug).
The great thing about Ext JS is that it gives me pretty much everything I'll ever need. Now I doubt I'll impress the "hype" crowd with that statement but I don't have to manage all those project dependencies and includes and various build systems. But at the end of the day, I don't care too much about the inner-workings of Ext JS because my finished products are so darn and good looking functional, and this continues to be one of its strongest selling points (albeit with a much heftier price tag these days, but it's still worth paying, IMHO).