I am currently struggling with NetApp support. After 2 weeks of constant effort they finally admitted of disk latency.
More digging revealed that they sold an under performing system at a inflated cost to run MS exchange 2010. NetApp do not add any value since Exchange do not need or actually utilise any of the features.
NetApp's WAFL( write anywhere) and insistence on using 4k block for disk io is the biggest design fault. Most systems nowadays uses bigger IO blocks to get more throughput with less IOPS.
Files on the disk also becomes highy files on the disk. Ironically they recommend to keep the defragmentation process turned off because there controller do not have enough comute powere to run the process in production. This is completed dishonest but very cleaver as it helps them sell more disks if customer doesn't dig deeper or don't have competence to ask right questions.
Another laughable design choice. Your size of SSD pool is very limited (12 TB on a FAS6000 series filer).