First thing first, it covers the full 3G bands (on both SIM slots): 850/900/1900/2100. This means it can get 3G (H+) on AT&T, T-Mobile, China Unicom and etc. Yes, I can get T-Mobile H+ as showing in above video, not sure it is 1900 or 1700 though.
It is true dual standby: incoming calls can ring from each SIM, even while any one of them is using data. You can let the call go into voicemail, or let it break the data connection and ring the phone immediately.
For $200, I think it is currently the best dual-sim phone. Others are over priced and/or not done right. The Sony Xperia M2 is similar and similarly priced with a larger screen (4.8" vs. 4.5"), but Sony is always over-priced (e.g. RX100) and/or done with some stupidities (like Samsung before Galaxy). I used to hate Moto too due to its add-on to standard Android, but this phone comes in clean Android.
The power and volume buttons are all on the right side, nice. The headphone jack is still on the top side though, like all other phones, stupid. Screen is great, anti finger prints on both sides.
Battery life seems very good. About 3% drop overnight with 3G on and drain seems quite slow while I use it as a WiFi Hotspot. Charging is very slow, I might be too spoiled by Samsung.
Although both SIM slots can use data (one at a time), it is better to use data on SIM 1, because Sipdroid won't see a data connection on SIM 2. Hopefully Sipdroid is the only app that has such a problem, otherwise such dual-SIM phones are not for hot swapping between two data service providers without having to physically swap cards. Not a problem if your intended use is one for data/voice and one for voice.
The phone comes with Android 4.4.2, I updated it to 4.4.4 OTA. I then unlocked its bootloader, flashed TWRP recovery and root it. All fine, follow this great guide.
To use it as a Hotspot through VPN, lookup table must be 60. 61 won't work for SIM 2. More detail here.
FM radio is mono, not stereo, hence not good for music but talk shows.
I bought this phone on ebay, from seller yumnatel08. It is an Asian version with Chinese, traditional and simplified, as one of the build-in languages. For a full list, watch above video.
Recently I bought another great phone, the MetroPCS LG L70. It is single SIM, but for just $50 you cannot get a better global phone including T-Mobile's AWS band. Unlock costs less than $2, Hotspot works out of box and 16:10 (not stupid 16:9) 4.5" screen is very eye friendly plus bold fonts; so it is a better choice than the Galaxy Light. Full Chinese UI out of box. If you need LTE, then the MetroPCS LG F6 for $70 is the one.
Lenovo K910 is the next dual-sim phone I would like to try, for its CDMA support and large screen. However CDMA is on SIM 1 only and SIM 2 cannot use data, otherwise I would have already bought one. This means it cannot use PagePlus for voice while using T-Mobile for LTE like the Galaxy S4. Still an overall better choice than the Galaxy S4 and later models, especially for its dual-SIM and $300 price tag.