I know - I tried. I have the Turbo one. Have 2-3 other clients on it too. You can chose the base one and upgrade from there. A good add-on is the railgun once you're live. That's a great tool. And if you get serious traffic, you can add on the performance bump too. We are working with them to get the memcached component working but that's been a plugin issue we're trying to resolve. Actually have their support working with us on it - very good team over there. Once that's done, I can share results with you in case you're interested in the future (that's the last think to worry about for your site).
Hope that helps.
Dave