Black VPN is the first VPN service I have used so I don't have anything to compare it to, but for me they have worked out great. I spent a lot of time sorting through the various providers before settling for Black VPN. I choose them for a number of reasons, aside from the fact their price is one of the cheapest around, they also seem to have great attitude towards the service they are providing, taking a look around their website I got the impression that the guys behind VPN certainly don't seem like the type who are going to screw you over. The payment is also really easy, you can pay for one month at time, which means you not tied into a longer term plan, like some other bigger providers.
Speed/Reliability: I only subscribe to the UK service so I can't vouch for any of the others they provide, but haven't had any problems with it. We only get 1.6 Mbps download rate but this is all we get anyway, as we share with our internet with our neighbours and the service is pretty crap at the best of times anyway. I live in Germany and use it to watch iPlayer and 4OD, and absolutely no problems with this. I connect through tunnelblick on mac osx and have never had any problems connecting, the service has always been reliable.
Support: For me it has always been good, quick answers to all of my tickets. I have noticed a few people giving it a low rating although noticed these were a few months ago, so maybe they have pulled their socks up a bit! Another possibility is they are night owls like me.
I can't say that they will be great for everyone, as I haven't tested their service to the limits, but if you find yourself in a similar set of circumstances to mine, I would definitely recommend Black VPN.