I agree completely! I had no idea what a dream virtual RAID groups would be. I love how efficient this Compellent array is. With my Hitachi system you would end up with a bunch of wasted space as non contiguous chunks all over the place. A Compellent array is completely virtual with how it operates internally and so it actually uses space correctly. My UNMAP is also working just fine with my SC4020. If I delete data off a LUN, or even within a VMDK, I can see that space free up on the SAN.
Now I can't wait to kick all of my Hitachi systems out the door and replace them with Compellents.
This all flash SC4020 is crazy fast too. My latencies are well below sub-MS and my throughput from one VMDK to another (testing large file transfers) is 400-500 MBps. I'm using 8 Gbps fibre.