First, there are many EliteBook models. New models have all kinds of CPUs up to i7 which is obviously faster than MBP.
In my office everybody has EliteBook and I have yet to hear about any issues with HDD or battery or anything else. Obviously that's just an anecdotal evidence, not very accurate but so is yours.
EliteBooks enclosures are made not from plastic but from magnesium alloy. If you are interested, you may read this article "Business-rugged HP EliteBook Notebook PCs: tested to meet Military Standard MIL-STD-810F"
EliteBooks also have much better graphics, better higher resolution screens (some models even had IPS panels) with RGB LED backlit option available (only white LED backlit for Macbooks)
I don't know, we have had nothing but issues with our elitebooks, the whole company uses them and I can venture to say 75% of them have had issues of some sort. I really miss the Thinkpads we had before, those were rock solid. I just looked at my notebook, it has an aluminum top or some sort of metal, the bottom is plastic.
Screen wise there is no comparison to my MBP screen. Speed wise as I said, my MBP "feels" faster.
Basically I use my MBP for web browsing while sitting on the couch or our and about, some email, chatting, skype, maybe ill use FCE to make/edit a movie 1 time a year and some very brief CS2 editing (I have a i7 extreme machine with Vegas Pro and CS4 if I need to do heavier things). I'm perfectly fine with its performance, I know there is better out there but why waste money on a new one when this one suits me fine