I've been doing a bit of research so why not post it up. I'm over Xiaomi and the Chinese smartphones so with few options (Sony, Samsung, what happened to HTC?), it looks like Samsung is the best option. There are quite a few models, here are the specification differences and current (lowest) prices on Lazada:
- A02S 3/32 PLS 720p - 3.5k THB
- A03S better ram/storage (4/64) and fingerprint unlock - 4k THB
- A12 better cameras (not by much), more storage(4/128) - 4.5k THB
- A22 much better cameras (including HDR and OIS), Amoled (but still 720p), more ram (6/128) - 6k THB
- A52 Amoled 1080p, IP67 water resistance, more ram (8/128) )overall better build and components - 11k THB
It seems obvious that if one wants a better screen and cameras (the biggest weakness of the A03S/A12), then the A22 is the one to buy. Yes, it costs 50% more, but if we are to have these devices for 3-4 years, then that makes perfect sense, especially with 6gb ram.
If one does not care about the cameras and can deal with a sad screen, then the A03S makes sense (with fingerprint unlock and 4/64). However, for another 1.5k THB, an Amoled screen (though still 720p) gets you more ram and much better cameras (including OIS and HDR).
And again, for water resistance, a full 1080p screen, more ram and even better build and components, another 5k THB gets you there. A bridge too far for my budget.
Overall Samsung has been pretty clever at segmenting the market. Xiaomi has had a good run of putting pressure on that, but their ongoing ridiculous UI disasters (including with Android One and the inability to not spam with its standard apps, nor keep personal data out of the hands of the Chinese government, means they simply cannot be trusted technologically nor ethically. Xiaomi's prices are no longer tempting when full costs are known.