As an avid Boost user for years, I've been using Connect because it was billed as the closest thing to Boost. However, now that Boost is out I've found myself sticking with Connect. I've just grown to love the look and feel of it.
I'm the reverse. I never used Boost for Reddit (relay was my drug of choice) and started with Connect as it was billed as most similar to a lot of the 3rd party Reddit apps. Now that Boost is out I find myself looking it more. I do miss gesture voting though.