I have a couple of GUIs to create, and took another look at my (very) slowly evolving MVP package. A small update appears below, but the question of the day is one of performance of MorphTreeMorph in its various incarnations. ClassListExample is very impressive and reasonably quick. SimpleGridExample is very nice, but quite slow. Profiling its opening reveals that it spends a lot of time making morphs, but that's not super surprising. It's the total time that is of concern. Any takers on why? I ask, because I am trying to create basic presenter classes for lists, trees, (more or less working), text (will be easy - I *think*), and another big item is multi-column lists. My objective is to be able to easily construct things that (unless told to do otherwise) automatically deal with the selected index, updates, etc. None of this stuff is terribly difficult to do when following the Polymorph examples, PharoCasts, etc., but hopefully we can have MVP and stop repeating ourselves at the same time. The next thing I am missing is a grid. Any strong thoughts on examples to follow/reuse, or things that should NOT be used for any reason? Bill