I would like some recommendations for providers and plans that will best suit traveling all over China over the course of the next 2-3 months.

I know there are many threads about 3G coverage, the best plans, the best providers, which phone you have, etc. So I know some of what I'm asking is redundant but I figured since I am traveling that may affect recommendations.

WHAT I OWN:
1. An unlocked iPhone 4S. I already use it here with a regular top-up China Unicom SIM.
2. An unlocked iPhone 4, no SIM.
3. A laptop
4. A USB 3G dongle from India, but I have no idea if it will work here.

WHAT I HAVE READ:
- You may not be able to top up minutes outside of your home province. I have done this in Guangzhou with my Yunnan SIM but I am not assuming I will be able to elsewhere.
- China Mobile supposedly has the best coverage but uses a proprietary protocol that only iPhone 4S's and later have? Is this accurate?
- China Unicom supposedly has the best 3G but doesn't work everywhere. True?

MY PLAN SO FAR:
I need Internet. I don't talk on the phone much. I will probably only use the phone for calling hotels, restaurants or the police in an emergency. My top-up China Unicom SIM draws on my balance for data, it does not have a separate data plan. Not only is it not cost-effective but once I start roaming it will be untenable. At least on China Unicom, I believe a separate data plans requires a six month commitment. If the math made sense then I would consider that, but it doesn't get around my roaming problem. So I assume it will just be better to get a data-only plan, use that for the iPhone 4S and the laptop (I'd get a China-working dongle), and move my China Unicom SIM into the older iPhone when I need to make a phone call.

OPTIONS:
If China Mobile will work on my iPhone 4S and whatever USB dongle I buy, and if they have a roaming-free data plan, perhaps that would make the most sense? Next would be China Unicom's roaming-free data plan, and then I'll just have to go without internet when I'm in the rural areas?

Another option would be to possibly get a local SIM whenever I am planning to be in another province long enough to merit the cost, but I would probably only do that as a backup for when my roaming-free data-only plan had no coverage.

Does this make sense? Does anyone have other suggestions? Have I done my homework correctly?

I see there are a bazillion little 3G data booths lined up around Yuangtongbei Lu. Can I get what I'm looking for there, or should I go to a particular shop?

Thanks.

China Unicom has monthly nationwide plans that include voice, sms, and some data for a pretty reasonable price. I don't recall having to sign up for 6 months. 66rmb for 50 min, 300mb data, and 240sms per month. Going over that amount per month the per mb or min charges are pretty reasonable and same nationwide.

Pure data plans will give you GBs per month with a lesser amount roaming, but still in the GBs. But usually they require a purchase of 500rmb or more in credit which is roughly 6 months usage maybe.

The 4s can't support China Mobile 3G.

Maps on ios6 for google and apple are less data intensive due to vector mapping, but probably will suck the most. Google maps on android can let you offline some maps.

Unicomm can revert to 2g when there is no 3g, but when I had Unicomm out in the rural area, the iphone was less able to pinpoint a location than with China Mobile 2g.

Considering the number of devices, you could purchase a mini wifi sim router. You plug in a 3g unicom sim to a small battery powered cube, and it provides wifi.

www.tp-link.com/common/subject/3g-router/TL-MR3020/