Would they be a good solution to get programs like Toontrack Superior to load into Sonar sessions quicker.  Typically, a 1 gig drumkit might take a minute or so to load into RAM.
I seem to prefer using all external drives too...all USB 2.  Any downside to this?
And lastly...  are there any SSD with USB 2.  Seems most are now USB 3??
 
thx

The problem with USB 2 and an SSD is that the traffic between the computer and the drive will bottleneck at the USB. USB2 can not even feed a fast mechanical drive as fast as the drive can do a sustained read or write. It does not matter if you are driving a smart car or a Ferrari if you are in a 30 mile an hour zone. Using an SSD with a SATA 600 connection, as most internal drives do, provides enough connection speed to use the full speed of the SSD.

Why not just use an internal SSD?? (considering all the pro's & cons)

A fast SATA-III SSD tops out at sustaining a little more than 500MB/Sec.
USB3 is necessary to achieve that level of performance (USB3 tops out ~550MB/Sec).
USB3 tops out ~40MB/Sec
Thus, doesn't make any sense to connect a SSD to a USB2 port... as you'd do just as well with a conventional HD.