Hi Ram,
Yes, the SSD does make a noticeable difference. The 64 GB limit is only in express though e.g. today we built a spec for a 100 Mbps link with two 128 GB SSD's.
The performance benefit of the SSD's that is applicable to Wanos is the IO per second, random reads/writes and the low seek times. Although not often, in some cases a good quality USB flash can out perform an old HDD.