I like how it works with my router, allowing me to connect from anywhere in our house or office without having an annoying pop-up window every time! It does seem buggy at times (especially if your internet isn't stable), but overall this has been great for us so far!! We're currently using openvpn primarily because we are trying out different providers/services - some of which require clients such as firefox etc., however spark labs allows easy use even when visiting websites requiring flash plugins.. I like how easy it is to set up, secure, and use. It has everything you should need to make sure your VPN is secure, including a built in DNS leak test tool. The pricing model (free for open source OSes) makes this one of the best options out there, since otherwise there would be little motivation to use it. Not much; works well. Security.