It will come (in fact it's next on my list), but right now I'm more interested in making sure the update progress works well and there are no surprises so that we can move the SSU to Jeremiah's maemo.org repository and start working on the next one.

There are no performance improvements (unless you were affected by the telepathy-gabble deadlooping bug, but that's pathological). If anything I would expect a very slight performance loss due to the updated binaries being a) not prelinked like in the Nokia firmwaer images and b) slightly larger due to the added code. Perhaps it's a side effect of rebooting, if you have for example a desktop or statusbar applet that leaks memory slowly over time. Before I started testing the update process my tablets' uptime was measured in months :-)