I never switched from a RAID 0, but I replaced a WD Raptor with a Sandforce 1 SSD.
First good thing in my case was noice reduction, but also system booted faster, and much more system is really ready to go after log-on and don't need a second "boot process".
Also applications start really fast and are closing.
The reason is not sequential transfer, the reason is the high rate for small transfers like the often mentioned 4k IO/s. These numbers are 20x higher on nowadays SSDs compared to HDDs.