I currently have a 4 disk raid 0 it is quite fast loading things no complaints so question I would like to move onto SSD I got the Kingston v100+ so read is around 240 max but my 4 disk raid benched 300 on long and short test of HD tach... So will this be a downgrade I know seek time will be waaay better should I forgo even installing this and grab a second one which should be able to pull 400 in raid 0. I did go cheap on the SSD I know but I will wait till the 500 gig ones get resonable before I would go high end.
Depending on which drives you have vs. which SSD you buy the HDDs in RAID 0 may be able to transfer large files more quickly, but the SSD will still be miles ahead in terms of access time. RAID doesn't do anything to improve access times, and SSDs have access times that are about 100X faster than a hard drive.
What this means is that you can expect the SSD to be much faster at tasks that involve dealing with a lot of small files, but not much, if any faster at tasks that access a few large files.