New hard disk for Lenovo X220

[ThinkGreen]

I've to upgrade my lenovo with an ssd, currently I've only a slow hard disk at 5400 rpm

Do You suggest a "complete" replacement of this disk with an ssd unity (128/256 gb) or could it be better to use the msata slot and continuing to keep the slow hard disk to storage "simple" data (audio, video, images) ?

[ZaZ]

I think a mSATA SSD as the boot drive and a platter drive for storage where speed is not as important, is the way to go.