Andy-h,
We've bagged the MSA/SAS configuration (this whole mess was the final nail in the coffin for that - though to be completely honest, we never really liked it anyway) and gone to the small 3PAR storage with FC switches. Yeah, the cost is higher - I fully realize that not everyone can afford that config - but it is a super reliable system.
And, no, I'm NOT - REPEAT NOT- an HP marketing type. Just a fellow end user.
Ken