I'm not sure about all the foreign teachers' experiences with City College, but I've known quite a handful of them as they were mostly shacked up in some apartments in Xili. Quite an eclectic group of people indeed. Lots of good conversations from people of many different ages, backgrounds, and citizenships. But I did hear about quite a lot that were coaxed into coming to China on any visa they can, typically a tourist visa. And even though many of them were native speakers, some of these teachers had a hard time applying for a proper work visa. So they were forced to make frequent trips to Hong Kong. Some even "purchased" a 10 year of some sort. Paid top RMB too.

As for the teaching experiences, it was a mixed bag. As you may or may not know, Shenzhen has a lot of residents who are not locals. The ones that have been there for a long time (10 plus years) are generally really well off because either the government gave them housing, which they were then able to rent out to newcomers and not have to bear any of the taxation (that is the responsibility of the poor suckers that arrived too late), or they were able to take advantage of the cheaper housing costs. Now, it's ridiculously overpriced. You think the American sub-prime mortgage, mortgage backed security, credit default swap financial crisis was bad? Wait until the market corrects itself in China. Those concrete flats in an ugly skyscraper are not worth 90,000 RMB (over 13k USD) or whatever the price is per square meter (10.76 square feet). Anyway, to make a short story a little long, some of their students were exactly, paid attention, and always participated in their classroom activities. Some students are simply remnants of the cultural revolution... you know the good ol' days of China when the intellectuals were persecuted and put on display for public defamation and the intellectually declined cranked out something like 200 million more babies in the span of about 10 years? Anyway, there has always been a class of enlightened Chinese people that really value education and love to learn foreign languages among other bodies of knowledge. But there are also way more that just care about getting married young (early twenties), having babies young, chilling in their concrete blocks, playing with their phones, and sitting around doing nothing all day.

So back to City College. Even with foreign teachers who knew not to go to China without a proper work visa, many were not allowed to receive their foreign expert cancellation letters, which if you know anything about the bureaucracy in China, this document is essential in order to transfer to another employer. Problem is many of their residency permits expired either on June 30th, which is totally messed up if you're trying to transfer, or July 15th, which is better but they often didn't grant this letter until just before July 15th. Luckily, Hong Kong is not China, regardless of how petulantly the communist party wants to insist that it is... along with Taiwan. So they can simply cross the border into Hong Kong or Macau for that matter to avoid overstaying their visas, which would result in a fine of who knows how much (10k RMB last I saw) and or jail time.

So I'd say that if you want to work in Shenzhen for a year or two. Sure, City college is an option. But if you're looking to transfer to another employer in Shenzhen or another city, things can get hectic as the staff at city college are pretty petty and vindictive. Personally, I think it's better to go to smaller cities because you have more opportunities to learn Mandarin and see what regular China is like. Also, your money goes much further. The part-time jobs make it worth it to stay in Shenzhen, but it could be difficult if you are not white person as the Chinese are pretty racist. Even eastern Europeans, you know non-native speakers, could get jobs much easier than natives with dark skin or Asian features.

So....weigh your options. Hope this was informative.