To finish with today’s stories about DoCoMo and its smartphone strategy, here’s an interesting poll that MMD Lab ran a few days ago.

Its satisfaction index on mobile carriers is quite revealing. DoCoMo retains the highest percentage of happy customers in terms of cell coverage quality. Almost 85% of satisfied subscribers, DoCoMo can brag about it. KDDI is very close, but SoftBank gets a paltry 52%. If you break down the number and keep only the very satisfied customers, DoCoMo has 26%, just behind KDDI. Softbank is again third. And far. 4.8%. Ouch.

For the design of handsets, you reverse the order. SoftBank gets more than 80% of satisfied subscribers, with DoCoMo just behind at 78.5% and KDDI at roughly 76%. The survey even asked if the clients were happy with their camera. While such a question sounds silly with the staggering number of different phone line-ups, here are the results: KDDI customers are satisfied at 71.2%, DoCoMo at 69.5% and Softbank at 63.2%. Not very significant.

Now, the study gets more interesting since it asked what people would do when the SIM unlock guidelines become reality. Will they switch? The status quo is favored by 30% of those interviewed. Loyalty is a big thing in Japan. Inertia is big worldwide. Remarkably though, the wish of 20% of customers surveyed is to be able to keep their current carrier with the iPhone. That answer, in second place, shows the big draw Apple’s phone gets in Japan. And why Masayoshi, Softbank CEO, is willing to fight to keep it exclusive -going as far as locking its cousin, the iPad.

And, yes, if you break down those numbers per carrier, you get 25% of DoCoMo customers who show iPhone envy. Lots of people would love the iPhone on DoCoMo in other words, if you extrapolate the numbers, that is.

We kinda knew that already, it’s only a survey, but still. It fuels right into DoCoMo current strategy: eyes on the iPad -getting the iPhone is a rumor similar to Verizon or T-Mobile stealing the thunder from AT&T in the US- and the ramping up of its smartphone line-up.

The survey was taken between July 16 and 21 with 2176 interviewees. No details on the statistical method.