Just to add to this. The initial beta of version 6 will be out in the next few weeks. However, it will not have the speed improvements enabled. These will be enabled as an option in version 6.1
The reason Syncdocs can be slightly slower is that it double checks changes that the Google server reports. We have found in the past that this improves the reliability of syncs, especially preventing duplicate files and erroneously deleted files. Our speed fixes will require extensive testing on many different data sets, link speeds and network reliability levels before we release them in a non-beta. Syncdocs favours reliability over speed.
What speed and type of network link, do you have, @egalvan?