Look like you confuse about 'large' and 'extend' format dataset.
Large format dataset can using for SAM, extended format dataset can using for SAM and VSAM.
Extended format dataset must SMS, but large format not.
If you want compress, the SMS is needed.
Striping dataset is another case of extended format dataset. It need hardware support, 'Sustained Data Rate (SDR)' is used to set up for striping dataset , and I think the hardware right now used by all of us support this.
We use extended format dataset and compress for SAM and VSAM in my site, it reduce the I/O usage (because compress) and increase CPU usage (because decompress), like dick scherrer explain: batch job cpu usage to compress the data will greatly outweigh what you currently see.
But when I/O usage reduce, the CPU comsume is reduce too.
So if you using extended format dataset for SORT, when the CPU environment is not busy, then the elapse time will reduce, and total CPU time not differ much with origianl, and the peck CPU usage will increase.
But when the CPU environment is very busy, the elapse time and CPU comsume time will almost like original job.
Striping dataset is divide data into multi part dataset to increase I/O in parallel. We use it to replace a EMC product-(TeraSAM), and it work fine.
Hope can give you some help.