To all the questions :
1.
http://www.newegg.com/Product/Product.aspx?Item=N82E16820167016
2, The failure rate on the Raptors in the HD database at storagereview.com is 25%
3. 400 HGB of applications won't fit on two 300 GB raptors in RAID 0
4. RAID 0 does squat for gaming or application performance. See RAID 0 articles on storagereview.com (<2% improvement) and anandtech.
5. I wasn't specifically promotong the 7200.12 as any 500GB per platter drive will do. Relative performance depends on what you are doing and you should pick the drive that fits your needs.
7200.12 has a DTR of 152 to the Raptor's 116....one of the reasons I use them in an NAS which all the office systems back up to. They are also the quietest and lowest temp drives among their major competition.
If gaming is the goal, then the 7200.12 is less attractive ... then in the instance stated, it's not intended as a source drive. The HD is just a repository for the "games you are not playing atm".
C:\Windows OS
C:\Crysis
C:\Far Cry
C:\Sims2
D:\Game 1
D:\Game 2
D:\Game 3
.........................
.........................
D:\Game 26
When you done with Crysis, FarCry, Sims 2 for a while, simply cut and paste the folder from C:\ to D:\ ....... and paste on C:\whatever you are playing next. This may require installing each program to C:\ (SSD) 1st and then copying it to D:\
If that's "too much work" buy a bigger SSD.
Personally, HD speeds don't bother me.....my machines rarely shut off and even when I open the laptop each morning, I don't much care how long it takes to get to the desktop as it's always there by the time I get back from getting coffee.