No RAID? Wouldn't even finish reading the page. Openly not a fan of RAID? Are you also not a fan of redundancy or uptime? I seriously hope you have reactive monitoring in place and restore quickly, otherwise a single hard drive crash will lose you 9-11 customers.
Single SATA disk pulling about 70 iops for 9-11 users? The is kind of scary. On just a dual core CPU, meaning you're pushing 4-6 VPSes per core too.
Wish you the best of luck with your new provider.