SATA II port multipliers for media servers?

[ctown6412]

Im still in the process of redesigning my media server and came across port multiplier adapters for sata II. I wanted to see if anyone has tried this yet for their media server and if there are any serious performace issues.

This is one of the multipliers
http://shop.store.yahoo.com/cooldriv...apomubrso.html

I plan on using raid 5 with a min of five 300 gig sata2 hd's to give me 1.2TB to start but I do plan on adding more drives when I need the space. This is where the port multipliers come into play. If I can use just two of the 3g connections on an Asus P5WD2L premium motherboard with the intel 955 chipset run from the port multipliers this should eliminate the need for expensive multiport raid cards I hope. I am looking at the 2.8 dual core p4 chip for the system with 1 gig of ram but im might go to the 3.6 if I need to.

This will be a dedicated media server for serving uncompressed dvd files, mp3's, digital photos and generic file server. As of right now 1.2 tb is the absolute least I need right now. I will likely add another 1.2TB on the second 3g channel as soon as the funds are there to do so.(1.2 tb in raid 5 costs$925 at current hd prices with the multiport adapter)

Think its worth a try or am I wasting time and money?
Looking for suggestions if anyone has any better ideas or things I should look at.