I ran into an issue when I installed a new Responsive Template. It's CSS was causing a conflict with Google Checkout's CSS which made the checkout button disappear. I put in a request for support and in less than 24 hours I was not only responded to but the Developer at Trinitronics, Michael had figured out what the issue was and provided me with the CSS override I needed to paste into the Plugin to fix this issue.
That impressed me enough to come here and write up a review which I rarely do. So if you are looking for a very simple way to manage anything you sell using Google Checkout then I recommend the few bucks to get this Plugin as it is a great time saver and if you do have issues Michael will be there for you.