I like the statement in their homepage: We don’t assume you are stupid.
I needn’t to pay for unnecessary management, which I could do almost by myself. And seems prgmr is the best unmanaged VPS from the reviews. Yes, it’s cheap, only $12/month for 512M, while others (semi-managed or managed) at least $20, like famous Linode, and even more expensive by some Chinese VPS providers. I purchased on Saturday, but could not find a payment link until Monday. I have to say the user interface is not friendly at all. Anyway, I paid on Monday and got the server set up in a few hours.
I set up VPN, nginx, php and the blog here, and until now it runs smoothly. The network was quite unstable in the first few days from China, and I even tried to find a refund way. It’s OK for me now, however, though still a bit slow here. No down time yet.
It’s a half a month review. So if you want a stable, cheap, unmanaged VPS, and you can suffer a bit the slow network from China, give it a try.