Every vendor does it. Welcome to the 2016 storage market.
However in the big table in the middle of the article, they show you raw, maximum and effective capacity. It could not be easier to understand.
For reference, the effective capacity is only with compression. It does not include dedupe, thin provisioning or zero copy snapshot savings. So you're always going to be on the winning side.
Its also worth noting (because the article skips it) that encryption is on a per-LUN basis or the whole array because it's done via the Haswell offload chipset, rather than via hardware drive encryption.
With drive encryption, you can only encrypt the whole array (all LUNs) which just adds unnecessary load to the storage controllers.
Well done to Nimble, great to see them finally fill this gap in their product range.