Just got a ZTE U960. For those considering it, it seems pretty decent overall but there are a few niggly annoying problems with it:
-- As mentioned by someone above, it treats numbers as being different to each other depending on if they're stored with or without international codes. This means you have three choices: (1) store all your numbers in international format. SMS messages will correctly identify the caller ID but calls won't. (2) store them in local format. Incoming calls will identify the caller ID but SMS messages won't. (3) store them both ways for each contact, which is time consuming and error-prone (you don't always remember to do it).
-- You can tell that the English translations were done by a Chinese person, and this makes the phone feel a bit cheap. For example, when the screen is locked, there is a button for "emergence" instead of "emergency" calls, when you dial someone and it starts ringing, it says "Called is Ring", and one of the profile names (which you can't edit) is "Slient" instead of "Silent"). There are a few other examples which I can't remember right now. There is also no English manual supplied, so you have to figure everything out yourself. This has especially been a problem for me, as I've never had an Android phone previously. Luckily most things are self-explanatory, but I still for example don't know what all the various notification icons mean, and the charts I've googled don't cover all of them.
-- One of the supplied GPS apps, CoPilot Live, is very unstable. It crashes frequently when you try to use it in "walking" mode, and doesn't ever close properly, needing to be "forced" to close every time. I'm not familiar with Android phones in general though, so this may be the fault of the app and not the phone. It comes with two other GPS apps though (NDrive and Google Maps Navigation), so this is not necessarily a big deal (I haven't yet experimented with the other two).
-- MMI codes don't work on both SIMs, which is annoying as my network provider uses codes (e.g. *100#) for checking balances and allowances.
-- You can't have separate profiles for each SIM. My reason for wanting a dual sim phone was because I previously had separate work and personal phones and I wanted to merge them. But that also means that I would like to be able to silence my work phone outside of office hours whilst still having it ring on my personal SIM. That isn't possible. Either the whole phone is silent, or the whole phone rings. You can however have different ring tones on each SIM, so planning to look into the possibility of adding a ringtone which contains no sound, as a workaround. There's no obvious way to add new ringtones, but I haven't spent much investigating this yet.
-- Contacts are saved by default into a gmail account, with no way to change this (e.g. so that it saves to the phone), and the phone comes already set up with an Etotalk gmail account, which so far I've not been able to remove and replace with my own (if you try, a popup states that a factory reset is the only way to do it). Because I know that this phone didn't work with google apps at all until recently, I'm reluctant to mess around with what is obviously a workaround Etotalk have applied. But I'm not happy about the phone being permenantly linked to a Chinese supplier's gmail account.
Apart from those issues, I'm pleased with it. Most of the dual-sim functionality works very well, with the only major exception being the lack of separate profiles. All calls, call log entries and SMS messages have a "1" or a "2" in their icons to represent which SIM they've originated from, and when you dial or send an SMS, you are presented with two dial/send buttons. Someone else in this thread mentioned that 3G only works on SIM2, but as my SIM2 is the one with a data plan, I haven't yet tried it on SIM1 to confirm this.