The big downside to the Sims offered in jpdm's link is the 90 day expiration; these Sims are actually fairly easy to buy for around y80 locally, but I would definitely pay double for a non-tourist Sim, even if doing so entailed a visit to a Unicom store. Unicom allows you to place Sims on "vacation mode" when you aren't in China.

I agree with jpdm that dropped VPN connections are basically a non-iissue for me.