Hi Al - as always: "it depends"- in this case, it largely depends on the nature and needs of your MQ application(s):
- what type are they (batch, CICS, WAS, ... , Client-based) ?
- what is/are the application patterns they use (response-reply, fire and forget, strictly asynchronous ?)
- is it about moving messages very fast or storing/forwarding very large messages ?
- and so on ..
The really good news: for a long time, and for many versions of MQ for z/OS, the IBM Hursley Lab maintains very exhaustive performance reports, as "Support Pacs"- actually PDF documents that you can download. There you will find very detailed "metrics" for whatever area is important to you.
Just search (google) for 'mq for z/OS performance reports'
regards, Marcel