Suffice it to say, I'm happy with the SIM because it allows me to use my Nexus One on the FOMA network. If I have to chose between 250 MB at ¥2,000 per month or unlimited data at over ¥10,000, the choice is rather obvious. I have a better experience with a newer phone, and the total I pay for cellular has decreased by 4,000 yen per month.
However, the data-only FAIR is not a perfect solution for several reasons, the most obvious of which is the need to carry around two devices. Also, Android still has issues with this type of SIM card, which may result in increased battery drain at least until the next Android version is released. (Ice Cream Sandwich will merge Honeycomb, which is designed with data-only devices in mind, unlike previous versions.) The only current workaround is to use the TalkingFAIR SIM, which is a standard circuit-switched SIM card.
Finally, while the FAIR provides the best value for people who don't need an unlimited plan, the price per gigabyte is still very high. The best case scenario with the FAIR is 250 MB per month at about ¥2,000 per month, this is not only twice the cost of AT&T's 250 MB data plan, the same amount of money would you 2 GB per month, an eight-fold increase in value.
But, this is not the US or Europe or Australia or wherever. And of course this post wouldn't be complete without a discussion of the data. :-)
To use exactly 1000 MB in 120 days requires 8.3 MB of data consumption per day. I averaged 7 MB and had about 150 MB remaining when the SIM expired. Two month ago, I predicted that I'd have about 400 MB remaining (gray fit line).
So what happened?
Of course in the end, I used a lot of the remaining data. Looking at the blue fit line, you can see that I would have had closer to 300 MB remaining if I didn't drastically increase usage about a week ago, as the expiration date approached. I totally stopped using wifi and started signing in to skype all day, which works great over 3G, by the way. The reason was not to eat all the remaining data, just be cause I could. Rather, I wanted to test skype some more and get a better idea how much using wifi was saving me.
The largest reason for the increased usage was the Google+ Android app. Of course I have it set to only upload photos on wifi, but using it displays a lot of user-posted images. Considering only my usage since I joined Google+, I've averaged 8.5 MB per day, after removing the final week's usage (light and dark blue dashed line). This would actually work nearly perfectly, resulting in 1020 MB over 120 days.
Additional charge added on 8/11/2011 (Chart is interactive)