I have 4x PS5000's (older model with 6x 1Gb Ethernet)
There fantastic, very easy to manage and perform well. Provisioning, growing and migrating LUNs to other nodes can all be done on the fly, makes life easy.
we got an Equallogic 5000X love it. nearly purchased new 10GbE one but need to wait a little longer to some $$$
highly recommneded. Feature packed and fully intergatable with other Equallogic models.