OK, San Migs - my reponse:

You admit it is not suitable for others, and that is good. I'm glad to see you are not pushing everyone MUST work on L visas. I am just curious why you relish doing so?

Everything has two sides. With an L visa, I can change jobs from province to province more easily and without compulsory medicals. I can wait and wait before taking up a new job late into a new semester. When I take a new job at those times, I can get one very easily as there are few foreigners in China available to fill such vacancies, and I have an extra advantage over foreigners outside of China seeking to fill late vacancies. Unlike them, I can arrive at the school within 5 days of being asked to arrive there. Chinese employers who need FTs fast and late will take me on gladly to get themselves out of a jam. And they tend to appreciate me more because of this. So, they will let me do my job with less interference as they don't want to end up with me doing a runner, mine wouldn't have negative repercussions. I couldn't be taken to task for breaking my contract, as mine is illegal in the first place. Also, I needn't worry about unfsvourable teaching reports that would hinder future job searches as I needn't supply one to a new employer.
I think have more freedom than FTs shackled to a system that needs compulsory medicals and residence permits. Of course there are negatives to the L visa way. But having a Chinese wife in a country that gives me almost no extra visa privileges for that, I take full advantage of the visa system that gives me 180 dayers whose expiry dates I have manipulated so that I'm back in my wife's hometown during semester breaks, a very suitable time to renew L's - I'd be back there anyway at those times. So, it's very convenient, just like killing 2 birds with 1 stone. As for visa costs, 160 RMB/ L visa, no entry type, for renewals for Uk citizens within China, but I believe American visa fees are double mine cost-wise.

Why can't a long term id card be offered, thus negating the need for stamps?

I believe I can get a 5-year RP more or less automatically now, as I've been in China on L's for so many years to date. I'll apply for one in January 2013. - I've had a two-year one before, which I unfortunately had to surrender when I left China for a vacation in the UK. I believe they don't issue two-year RPs these days. I could still teach with one or with an L, though either way is of course illegal. Right now I'm legal here as I'm not working. I doubt I'll be back teaching, but if a suitable offer arose, I would give it serious consideration.

Have a good festive season when it comes!