Internet service may be ranked according to two speed categories, as follows:
DISTANCE TO SWITCHING CENTER
The distance of your apartment or more appropriately, CPE (Customer Premise Equipment) aka ADSL Modem from the carrier's switching center will determine the raw speed quality.
DOMAIN NAME SERVER (DNS) RESOLUTION
The speed at which your ISP (Internet Service Provider) can resolve domain names (eg apple.com) into it's IP (Internet Protocol) Address (eg 172.16.xxx.xxx) may also be the cause of apparent slowness. A fast way to test is jump to baidu.com and apple.com at the same time. Baidu USUALLY loads instantly. Apple may timeout or take several seconds before it loads. This is because the DNS server may be overloaded (probably). Larger companies such as China Telecom etc "usually" have heftier equipment.
Finally - there's the carrier requirements in China for internet forensics. Keeping track of everything everyone does consumes tremendous processing, storage, and bandwidth. Outbound traffic (out of country) can be incredibly slow as it bounces around the ISPs servers, content filters, etc on the way out of one of the several "gateways" out of China.
Foreign VPN (Virtual Private Networks) can sometimes speed up the perceived internet speed - but that depends heavily on how fast your Chinese ISP can resolve that VPN address.
MOST connections out of China these days ricochet around an ISPs infrastructure for seconds before being allowed out - VPN or not.
For 3G systems - best to probably go with either China Telecom or China Unicom. China Mobile inherited China Rail Telecom's infrastructure (2% of China's market share before the merger), so China Mobile's aggressively trying to build out it's broadband network. Unicom got China Netcom and China Telecom is - well China Telecom. Both have strong broadband networks.
You may also try out the second tier ISP providers such as AIPU and Great Wall Broadband - but your mileage may vary (YMMV) as they usually depend on pipes from the big 3 to exit China.
I use Aipu - speed is faster, but DNS resolution sucks all around (both for domestic and international websites). Even taobao is sucky to connect to - but I've used aipu connections at friend's homes and speed is blistering fast.
I'll switch to great wall after this contract is done - see if that's any better.
FYI asking the gorilla installers the distance from your apt to the switching center - may as well be speaking yiddish. My connection looks like a tangled clothes line fed out through an apartment window. Gorilla installers. Good thing we don't have typhoons here.