Procurve is nice stuff
At one point, a firm I worked for was one of the largest area resellers (multiple states) of Cisco hardware. We deployed some procurve switches internally, and loved them. Within 2 years, nearly 80% of our new system deployments were procurve, using Cisco only where it was insisted upon with blind passion. Those who took in an HP loaner switch and did real comparrisons almost always chose procurve.
The stuff is cheaper with the same or better performance, is more modular, has higher availability, uses 100% open protocols, is easier to manage, and has lifetime warranty at no additional cost.
Having done several large scale swap outs, I'm not surprised it took HP 3-4 years to completely roll over. Some of the ingrained Cisco proprietary stuff can be a pain to remove once you're using it (EIGRP), but with some planning, it can be removed, and companies are surprised how much greater avaiablity they can get from lower priced products. ...especially when you have more than 2 datacenters in a complex and want fully redundant grid pathing instead of simple loops, where large centrally managed wifi deployments are needed, or when multiple different backplanes are needed in a single location (cisco makes you buy a giant 6500 series switch, HP has a 4u unit that does the same, and with 1 fewer single point of failure, and no additional licensing).