I’d say the checkout itself is quite good, though I’ve had to put in a couple of frigs myself in relation to default states/cities as I have variable shipping prices depending upon location. However, I’d say their support is ‘cowboy’ level as I’ve seen with a number of module developers. Saying that, I’ve been using it since then with no problems.
That Presteam one sounds interesting, might have to take a look at that. When I bought the knowband I think it was the best available at the time.