Heterogeneous RAID5 or single drive?

I currently have a 6 disk RAID5 setup with a heterogeneous mix of 300 GB hard drives (maxtor, samsung, western digital). I use a 3Ware 9650SE-8 hardware RAID card and have the battery backup.

This setup gives me roughly 1.5 TB of usable storage. I also have a 1.5 TB hard drive. I plan on using either the 1.5 TB drive as my backup, or use it as my primary and start using the 6x300GB hard drives as my backup.

According to http://www.tomshardware.com/review [...] ,1662.html, I'm likely paying a substantial penalty when it comes to access time. On the flip side, I'm getting massively better read transfers and substantially better write transfers.

These days, I mostly use my computer for playing games. So, if I want to, say, minimise my Windows and TF2 start up time, that sort of thing, which option is best? Use single 1.5TB drive for my system? Or use 6 disk RAID5 setup?

What are your current HD transfer speeds with your setup using HD tune with settings on acurate?

If I use the 1.5 TB drive as my primary, I'll move all the 300 GB hard drives to a secondary machine which will basically just serve as a backup. I'll also most likely ditch my hardware RAID card, just use software RAID5 on the secondary machine. The 256 megs of cache on the RAID card is nice but not a huge win.

My recent experience has shown that to have a good backup, you need to eliminate all single points of failure. So I'll either have the 1.5 TB drive in my desktop and all others in a secondary machine, or the other way around. I mean, they'll both be plugged in to the same power grid and in the same house (data not sufficiently valuable for off-site backup), but that's all.

For roadrunner197069, not sure what my current HD transfer speeds are. Toms Hardware benchmarks show access times are likely to increase from about 14 ms to 30 (single drive to RAID) but the rest of the specs would improve.

For br3nd064, I actually have a WD Raptor as well, probably start using that for the OS and games.

At this point, I'm most likely going to start using the 1.5 TB drive on my desktop, move the 300 GB hard drives to my secondary machine and use that to back up my desktop, and sell my 3ware 9650SE-8LMPL (and battery backup module) on eBay.