I love the 925 because the 920 is a bit bulbous and in most of the colours it comes in, it looks like a toy (to me at least), whereas the L925 is slimmer, available in sensible (some may think boring) colours, has metal surround, and it just oozes class. The 16GB RAM has never been an issue for me, but some people store a lot more on their phones than I do, so perhaps it's not for everybody.
It also has a great screen and great camera and is buttery smooth, though these aspects probably aren't much different to those on the 920, hence the very small difference in the names of the handsets 920 vs 925.