I use Solaris zones a lot.
We've got a number of X2200s, in two variants. Some just run web front ends, and are fitted with SATA drives (once running, the only disk activity is the web server logs); the database back-ends have SAS drives.
OK, so the SAS drives are expected to be a bit quicker - we did get them for that purpose. Based solely on the rotational speed, there's about a factor of 2 difference in performance.
However, if you take zone creation time as a metric, the performance difference is rather larger than a factor of 4. Something else makes the SAS drives fly and the SATA drives crawl.