There was a time not long ago when Dell was the de facto choice for Windows PC purchases. Their products were pretty good and, most importantly, their extraordinary size allowed them to sell very inexpensive computers. I had a CDW rep tell me a few years back that they simply couldn't compete with Dell's prices.
However, things have changed now. Initial quotes on about 50 desktop systems, several laptops, and some other equipment came back with CDW and HP both handily beating Dell in terms of price. Dell's turnaround on providing the quotes and the sales staff were extraordinary (Dell seems to be undergoing a real renaissance in customer service), but for most of us, it really comes down to the bottom line.
In all fairness to Dell, the sales reps are seeing where they can go on price and working hard to beat the other prices. It remains to be seen how exactly that plays out. I'm also deciding just how much my time is worth to me: CDW's rock-bottom quotes include me installing memory upgrades and the PCI wireless cards we need on Acer or Lenovo desktops; HP's turnaround time on tweaks to the quote just can't match Dell's almost instant response to inquiries.
It's also not clear how much of a role brand loyalty plays. We've had great luck with a round of HP systems (desktop, laptop, server, and thin client); the same can be said of a previous round of Dell equipment. Is Acer the Kia of computers? Cheap prices, generally great products, and uncertainty about some shaky early product offerings?
I'll let you know if Dell pulls this out and beats everyone else. To be honest, I don't think brand loyalty makes much sense in this arena; PCs are PCs, after all. It's the bottom line that will determine who gets this bid.