I have a MS G8 on my office, 3 to 5 people using the NAS.
I use one Intel SSD for read cache, two Seagate 4Tb 7k2rpm and a 2Tb 7k2rpm drives.
The SSD cache made a big difference for reading small files, but we also write hundreds os small files all time, and the save times are becoming very large as the projects grows.
I just ordered another Intel SSD and a HP P212 Raid card. Soon I will have enought ports to play with my drives.
I will show you the differences.