I think your two main problems are going to be the size of the text file output at the end and limiting access to the filer's command set. Ie perfstat runs statit, lun stat, and other DoT commands via the RSH interface which means operations manager and other tools will struggle to run other commands during the same period, if the DoT tools clash. As perfstat runs just one command at a time for the interval period set performance cost is not that high unless the box is total maxed out. In which case it could be the straw which breaks the camels back.
I tend to use Operations manager and my autosupport to work out when the 'interesting period is' and then drill in with the CLI command during the next interesting period. If you are not sure which sub system is giving you problems or if you need host side data perfstat is great. Just a case of setting the correct interval and repeat period. Again the commands in perfstat act sequentially so if you make the interval to big it may miss what you are looking for and if it is to small, there will not be enough information. I normally use either 10 minute or 30 minute intervals and repeat 3 times but no reason why you could not have 30min repeated 48 times. - How ever this will be more that 24 hours which is reported on.