Visa garbage

Ok folks, any seasoned expat here know the best/fastest/cheapest/most efficient way to swap visas? I'm currently on a student X visa and my company *finally* came through with the invitation letter. Already did physical, provided proof of my *expertness level* and green lights all the way. Do I really need to go to HK to change the visa??? Is there any way to do it in mainland? Better yet, has anybody here tried just mailing all the paperwork back to the their home country (for me the USA) and pay an agency just to process it like a new visa then have it mailed back to China?

Best,
Jon

Normally you enter China on a single entry Z Visa. With all the right paperwork, you will get a working permit first. Once you got this you will get a residence permit.
Also normally, a Z-Visa for employment purposes is only issued in your home country, so you'd probably end up flying home.
I've seen many people coming and it was, except for one case, always like I said - but TIC, so there may be a way.
I sent you a PM with the contact of a visa agent.

Good Luck

You need to exit the country, so that you can then apply for a Z visa which essentially is a temporary visa that implies you intend to take up paid employment in China, and allows you entry to do so (just remember the Z visa does not have a long validity date as it once did). Generally speaking the Z visa cannot be granted when you are in China already, you are required to exit to gain it, and usually that means back to your home country (though this MAY NOT always be the case). It's a pain in the arse, but them's the rules.

Once you have the Z visa issued by the Chinese embassy overseas (gained by use of the invitation letter you mentioned already), the Z visa allows you to come into China, then after completing all that's required; medical, employment contract, business license, bank account, place of residence registration (this is important and your responsibility) etc, then your passport will be given to the alien entry and exit bureau so that your Z visa can be converted to a temporary residence visa/permit (AKA work permit) (usually only good for 12 months). The employing company will usually assist you with much of what I've outlined, but just keep in mind that you can be liable for some of the shortcomings in any event there are any. Read my lips... having the correct visa and its appropriate validity is YOUR responsibility!
Also check your home countries taxation laws...
Yes, you have already undertaken a medical for your X (student) visa, but you will likely be required to undertake another, though if the prior one was within the past 6-12 months you could try to see if they'll accept it.

Hmm, possibly you might not need to leave as you are a student you are a resident, when you start work you'll still need to be on a residency permit. The Z and X visas are temporary single entry visas that last a few months, to allow a residency permit to be processed, and you already have that. However your purpose of your residency has changed from 'study' to 'work', so there is a likely hood that you'll need to go to Hong Kong, or the company you work for could be able to take care of this at the local Gong An. All depends on the local rules. Yes normally people need to go to Hong Kong, but that is usually people changing from business or visitor visas to Z visas.

Hopefully your application might be seen as an annual renewal of a residency permit with a change of purpose.