Firstly, I'm really excited about Polymer and I'm having great fun playing around with it. My post is really a comment more than anything else but any salient tips, tricks, do's and don'ts is appreciated.
On my journey I have spent a bit of time looking at core-splitter. I've been trying to replicate a data rich interactive interface that we had written in WPF previously. One thing I have noticed is that as a consumer you need to do a lot of plumbing in order to make use of the core-splitter element to stop bad visual effects and deal with resizing. You can see what I mean if you put a core-toolbar as a left element of a core-splitter and move the divider all the way to the left. Lots of bleed through to the component on the right.
Now, my CSS Kung-Fu isn't the best and I'm sure I'm missing several tricks but from an implementation point of view the lack of an easy to use resize framework might result in a lot of boilerplate and workarounds to get suitable use out of core-splitter and avoid bad visual effects. Does anyone know of any plans to work toward this?