I'd say it depends where you live.
- Battery life. There is not even competition. +2 hours of web browsing, 4 hours of watching movies, 4 hours of playing music, 1 hour of youtube HQ video watching, navigation software for 45min, some sms and calls, some emails. Both SIM cards on, one with 3G. Data connection on all the time.Google, whatsapp,viber,facebook sync on. Wifi was off even. Did all of this in 16 hours of time, and as you see, all of it require screen on and the web browsing+Youtube typically uses a lot of radio power., and ended up with 55% of battery left. My girlfriend on an S3 did about the same and it took out all her battery + again 40% of battery after recharge.
I typically do 1 hour of web browsing, some emails + whatsapp + viber + 1 hour of Youtube video, and an hour of music. In the evening, I have 70-75% left so my biggest problem is to recharge or let it go another day
This was my main reason for buying this phone and so far, it has not let me down.
- Performs well. Not the fastest on the market, but it performs well, stable, applications are fast. I don't use it for games, but I did install Ingress to test, and my performance was not worse than an HTC M8... For the normal use, as you and stympy are planning, it's more than sufficient.
- Price : under $250 is a bargain for what it has to offer you
- Modifications : it's pretty easy to flash your phone with a new ROM
- Magnetic case recognition : it's a stupid little thing, but I got a MOFI magnetic case with it, which automatically turns the screen on/off if you open/close the case (even unlocks it). I got instantly used to it, and love the feature. Only seems to work on stock ROM though...
- Back camera : works well, fast, and takes good quality pictures. Lot of filters in built-in SuperCamera app.
- 3G Signal quality. That's why I'm saying it depends on where you live. If it's in a city, and you are almost always there, with good 3G, no problems. But if you go places where the signal coverage is less, then 3G is gone really fast. (I compared to other phones, and while they typically have 2-3 bars on 3G, I'm already falling back to G(Edge). This might be because the Chinese version lacks 900Mhz 3G support, and if I flash a modem with 2100-900Mhz, my second SIM card doesn't work anymore (and not sure if it really does 3G 900).
However, the 2G signal on both SIM1 and SIM2 is holding the same as any other phone I compared it with.
Also, sometimes 3G H+ speed is all of a sudden capped at 30 or 50K/s, switching the data connection off and on again solves it, but it can be annoying. Might be related to my modem version too...
- MTK related issues: this chipset has some issues that can be solved, but you need to be a bit of a tweaker to do it. Mainly GPS and modem require some problem solving. Right now my modem is good enough, and my GPS gets a fix in under 20 seconds, but out of the box, my GPS didn't work well at all, and I had bad call quality.
- ROM support: the device isn't that popular outside China and Russia, so English ROMs are not updated that frequent. KitKat ROM available but unstable. The Chinese ROMs are well maintained and pack a lot of extra features (VIBE, Stock) as compared to ROW, but I don't speak Chinese
Coming from an HTC phone, I'm used to a lot of XDA support, frequent CyanogenMod updates and fixes and so on. I might have been spoilt
- Community support : XDA has the basic forums for this phone, but nothing compared to 4PDA. So if you read Russian or Chinese, there is a lot out there. For English speakers, it's hard to find answers to some questions. However, a lot of issues you might encounter are typically chipset issues for MTK6589, and what works for other phones with this chipset, usually also works for the P780.
- Heavy : if you have an S2 right now, and switch to this one, it will feel like a brick in your pocket. You get used to it straight away, but if you pick up another phone like S2 or S3, they feel like they weigh nothing
- Front camera : only 0.3M, and that is really noticeable. Quality of front camera pictures is ..well...bad. Selfies are not worth it, and video chat is ok but was better on my 4 year old HTC phone. People notice that quality is low when video chatting with them.
Interesting software for this phone
- Keeping my screen on while using the phone (Smart Reading) : standard in VIBE, but on other ROMS, I have Gravity screen which works a lot better actually.
- XPosed+GravityBox support : tweak your phone any way you want
- Lenovo SecureIt : nice features, and although I think I don't need it, it's quite good. Chinese version even better (with built-in ad blocker!), but I don't understand it
- Lenovo PowerManager : great tool for monitoring your power consumption, with a lot of features like freezing apps, and detailed overview and estimations are pretty accurate (I also use GSAM because it gives me better statistics)
- MobileUncle tools : you cannot have this phone without this app. It lets you tweak everything, like GPS settings, Headset volume (because the default max. volume is too silent for me), and so many other settings no other tool gives you access to. It is a must.
- SuperCamera and SuperGallery (built-in) : really great apps, camera has many features and takes great pictures (main camera that is)
: if you know what rooting and flashing is, and have no problem doing that, then this phone is awesome. It's an ok phone out of the box, but tweaking it turns it into a great phone. You will probably have to overcome some nasty issues you wouldn't get on an HTC or a Samsung.
If that is ok for you, go for it and you'll not regret it. Given the low price, if it really, really doesn't work out, you're not out $600 at least...
I just love, love, love that I never have to worry about using it a lot and running out of battery. Even after using it to charge my girlfriends S3, there's plenty juicy left