Intel Matrix Raid 0/5 for data and SSD for system ?

Hi ! Getting a new hobby has forced me to replan data storage and access. TBH I've no experience in Intel Matrix Storage or SSDs so please be patient I've used quite a lot of time for research but I'm with inconclusive results. So asking here o ye mighty computer nerds and data enthusiastics

Rig will be for : Playing virtual instruments. Max 2ch recording via firewire audiointerface.

Rig will also be for : Casual gaming , media storage/playing and downloading ,,, stuff

What I allready have: E6750+4GB+HD4850. Virtually silent cooling and power solution in modded Antec p180. 4 x scythe SQD1000 for 3.5" HDDs. XPhome32bit.

What I'm planning to get based on data mined : Gigabyte EP35-DS4 (TI chip for firewire + I was happy with p35-ds3r while it lasted) , 4 x 640 GB Samsung F1 or W.Digital GP , 32GB 2.5" SATA SSD - MLC.

Planned configuration : Trancend SSD for system. 4 HDDs Intel Matrix-0/5raided as relatively small 0array for samples , recording and other quick access tasks + large 5array for system and 0array backup images and media files.

Question 1 : This SSD compared to 2.5" HDD of same price category in system drive use ? All I was able to find out was that it uses slower memory than some other SSDs (MLC instead of SLC hence the lower price $65~70vat0% in europe).
Transcend recommends SLC but how big a difference is there? Boot-up time is of no interest since this rig will boot only if necessary so I can live with 4 sec slower boot Application launch times and overall performance once booted-up are of interest.

Question 2 : Does the Intel Matrix work as it's been advertised ? I've never used that feature. Will the CPU usage of this software RAID be a problem (peaking) ? Is there (unwanted) activity in raid5 array if no application uses it and will that slow down streaming data from/to striped performance array.If the whole matrix is pulled out of ,,, matrix I think I'll go :

1 - 320GB - 100GB for system - 200GB for samples&recording backup
2 - 320GB - 200GB for samples&recording - 100GB for system backup
3&4 - TB Raid1 array for media files.


Please point out the things I haven't noticed too for I really don't want to **ck this rig up Music gear will eat up most of the money I've managed to scrape so no high-end-$$$-solutions iyp.

Thank You so much in advance.