Back in May I ran a couple of posts on Dual-SIM phones to see how they work in practice (see here, here and here). The secondary purpose of the exercise was to give the phone afterwards to someone using several phones simultaneously due to frequent traveling to different countries and friends in those countries preferring to call and text local numbers.
So while the phone served the purpose of reducing the number of simultaneous phones to be carried very well it had one major disadvantage: No QUERTY hardware keyboard. I was hoping that the dual-SIM capability in addition to Android and the possibility of Internet access and apps would compensate for the inferior text input capabilities of the on-screen keyboard. But it turned out that it didn't.
Even after two months I still got complaints of how cumbersome it was to use the virtual keyboard and calls were frequently missed due to Android's feature of setting the loudness level of the ring tone in idle mode via the buttons on the side of the phone which were often inadvertently pressed.
Back to two phones (+ a third one) then, the QUERTY hardware keyboard of the old phones have prevailed over dual-SIM. Which shows that there is a market besides the main stream where usability is compromised for a bigger screen and a slimness. Hm, that makes me think of my good old N95 and how fast I was with T9 text input and navigating on web pages on the dial pad. Sigh.