This battery here pulls no deep hole in your wallet, but is still very valuable, because so much can prolong the life of my "Xperia active" so. (Note in the margin: a pity that there is no comparable phone more: waterproof, compact, ANT + and barometric altimeter)
The original battery lasted less than a day, this one I need to recharge every other day.
Respect. Heat generated during charging or use, I noticed nothing negative.
The battery fits perfectly well on the dimensions, because you read so other batteries, partly scary stories (fit with a file and so).
Have me for my "Xperia neo" even a new battery from the same manufacturer brought, and there applies exactly the same thing.
=> Strong buy recommendation!