A step forward
Getting a fully functional EQL into a blade chassis is a real boon for Dells Blade lineup. Dual controllers and having the full lineup of disk options (SAS, SSD, NL, Hybrid SSD+SAS) makes it very flexible.
Regards the accuracy of the comparison, a P4500 Left hand pair would be the closest comparison in terms of performance positioning, but the lefthand stuff lags way behind the EQL lineup in terms of performance, density and simplicity, plus its rack mounted - and this Dell sponsored comparison is about blade integrated storage options.
The HP storage blades do however offer you a way to put a dozen SSD's on the PCI bus of any adjacent blade for maximum IOPS and bus speed latency - something Dell can't do at this point in time - this is great if your running high IO SQL or similiar, and want ns (bus) rather than ms (iscsi) disk access latency to your SSD's
Practically - I expect that the Equallogic blade will be a great fit for building out dense DC deployments in a physically resiliant manner - but HP have the edge when it comes to building high performance storage right into the chassis - its a shame the VSA solution is so horrid. I'm hoping for a baby 3PAR blade for the c7000 at some point down the line.
PS - One VERY important point not highlighted above - the Equallogic can be slid out of the rack while live to hot swap dud RAID disks or controllers as it has a cantilever arm and ribbon cable attaching it to the backplane - the HP blade storage VSA appliance needs to be taken offline to get at the disks in the event of a failure - meaning downtime for your storage just to replace a spinner... worth noting if uptime is important to you.