One of the problems with Android Dual Sim phones in general is that unless the user has good knowledge of Androids (rooting, customization etc), its very difficult to get the best out of any device. Not to mention most of the good ones are targeted for Chinese release, which makes then hard to use unless installed with customised ROM. and the Galaxy S DUOS (and international version of Desire V) has taken that hassle away from users.
Fortunately many reputable Chinese suppliers will provide customization, either for free or for some nominal fee such as $5.00 US. With the custom PROM Google store is often installed and Chinese apps removed. Plus one has root permissions. Thus Chinese phones can be very nice in this respect. One need not be an Android expert.
Hence having to figure out how to root the phone is not an issue (for the phone comes rooted and already setup for western users with such custom proms).
But it IS important to select the custom PROM when ordering. Etotalk for example, offers such a custom PROM service.
The Chinese ZOPO ZP500+ is my 1st Android Smartphone. IMHO it is very easy to use and from what I have seen no different in operation between this Chinese brand and that of a Samsung or HTC or other Android manufacturer phone. Android 4.0.4 is Android 4.0.4 independant of what phone it is installed ON. With the custom PROM (cost $5 upon phone purchase ) there are no Chinese apps to remove. Googlestore is installed.
Having now compared my ZOPO ZP500+ to the brand new Samsung Galaxy S Duos, I am glad I saved the extra money did not go for the Samsung Galaxy S Duos (and I obtained a functionally superior phone). Having typed that I wish the owners of the Samsung the best with their wonderful phone ... as the Samsung Galaxy S Duos IS a nice phone (albeit relatively poor performance). I simply prefer the dual core CPU (with better performance) and North American 850MHz 3G coverage that I can get with the Chinese ZOPO ZP500+ that I can not get with the Samsung.
Having typed the above, I definitely agree that it is caveat emptor with Chinese phones and Chinese suppliers. One MUST research the quality/reliability/stability of the Chinese phones, and one MUST research the reputability of the Chinese supplier before purchase, where that research goes a long ways (and saves money).
IMHO the equivalent of that research is what one gets by paying the $100 US or more for a lower performance/less capable Samsung duos, is the significant benefit of the Samsung reputation.