Thank you for the reply. The mobile site looks sufficiently functional and much lighter weight. I have a decent 3G signal right now but I'll test it next time I don't.
The major pain is once the 'trap' has been inadvertantly sprung, I am blocked for a period of time (up to 30 mins in my experience the other evening) and there is no way back, other than to sit and wait, or try to change network (and so IP address). I assume this will apply to the mobile site too, unless that doesn't use the distil filter.
I assume this piece of software is primarily there to identify non-browser clients and implement rate-limiting, i.e. more queries than a human being could reasonably issue. That's always going to be a challenge with a fixed-price, all-you-can-eat payment plan.