The latest development version of the Spring engine is worth using except for the fact that many people experience awful performance. Polling and anecdotes say that the problem is system specific and I don't even think it is directly related to the age of your hardware.
The benchmarking tool is now sufficiently advanced and simple to use that everyone should be able to run a useful benchmark. In short
Run a BenchmarkEveryone Windows user should be able to do this (and Linux users if they can run ZKL). If you complained about anything to do with 91.0 (desync, poor pathfollowing) then run this benchmark. Any benchmark is helpful, not just the ones that have problems with the new engine.