One thing I don't particularly like though is Sencha's EXT-GWT, or GXT as it is known. For those that don't know, GXT provides an abundance of widgets including a fully featured Grid. This is of course highly enticing, but what I've found is that GXT appears to be an all-or-nothing proposition. GXT is more akin to a framework than a toolkit because it effects how you lay out your code. What isn't clear to me is why it has its own layout architecture and its own event architecture. That's just confusing!
I'm starting to think that GXT plugged a few gaps in GWT 1.x and is becoming increasing less relevant. GWT 2.x deprecates a lot of GXT; even GWT 1.6 introduced a new event model.
Don't even get me started on GXT's Grid separation of concerns; its one of those widgets that likes to influence how the data transfer objects look. Plain wrong. The whole loader concept is terribly confusing as well.
I feel that if GWT's TableCell was as fully featured as GXT's Grid then no one would probably use GXT.
Perhaps I'm being a little harsh though. GXT widgets present nicely. It is just that they don't just "slot in"; you've got to buy into all of GXT to use a little of it.