The release notes for version v0.10.0 announce "major space saving gains for the blockchain, despite the performance improvements".
How big are these saving gains ?
User /u/blasium reports on Reddit that:
FYI: The blockchain went from 17 GB to 8 GB for me
The exact decrease may vary depending on your setup (such as OS and filesystem).
Mine went from 13gb to 7.6gb for me so yes, the 0.10.0 version is definitely more compact. I run the 64 bit linux version and built the binaries on my machine. The old version was running 0.9.4