I ended up rolling back to XP on my Acer Aspire One.  The boot time was annoyingly slow, and overall the machine felt sluggish.  I made some attempts to minimize the strain by adjusting visual effects for best performance, but that did not make an appreciable difference.  None of this was unexpected.  XP is snappier with a much faster boot and more responsive operation on the whole. 

One issue that I have noticed is painfully slow wireless connectivity.  I fixed this by going into the Device Manager and opening the properties dialog for the Atheros Wireless Network Adapter.  On the Advanced tab I clicked on Power Save Mode and set the Value to "Off".  This lets the wireless connection have its fill of power while running on battery.  As I'm sure you can guess, the downside is that it does in fact use more battery power.