I just bought an Acer Timeline M3 quite cheaply. I wanted it because of its portablity and also the fact it had a 640M. The CPU turns out is pretty good, it is an i3 1.4 Sandybridge, but is way out in front of the C2D in my M11x. It came with a 500Gb Hitachi drive and a small SSD which is 20GB. Ok, so that looked great...I imagined it used the Intel Smart Cache and sped up the slower 500Gb drive as Intel intended...right ?
WRONG ! All that was on this 20GB ssd (and it is pretty rapid according to Atto) was Hiberfyl.sys and the recovery partition. This is so you can resume from Hibernation quickly.....
Sort of like buying a BMW M5 and removing four pistons to store lemonade and a warning triangle for a comparison of usefulness.
It took some tomfoolery to re-install windows on the SSD (still got 7GB spare on 18.6Gb total) and then put all the other stuff on the HDD. Seems zippy...but just be warned that not all hybrid SSD/HDD setups are setup with common sense in mind.