I bought an OpenVZ VPS from them and I'm really satisfied. Why? Here's why:
UNBEATABLE PRICES: I've searched many sites for VPS and vps6.net offers the best prices around according to quality. They're really cheap but they're better than any other I had before.
UNBEATABLE SUPPORT: I had many questions and asked for help many times to set up things on my server, but they were always there for me and helped and resolved all my issues and questions. I personally preffer Chris from their staff, but they're all good.
INSTANT SETUP: the setup was instant and free, not like other companies that make you pay for setup and deliver your product after hours.
What else? You can RESELL their VPS services with ease and whitelabel for free. Where else could you find this feature?