When I started at my current employer 12 years ago, it was a Compaq shop with the exception of an old HP “coffee table” server (I think it was the LH line).
I was so impressed that the thing was still in service with little in the way of maintenance, that when we bought several new servers, I went with HP on the recommendation of our software vendor. About six months later, I bought 5 more. The next few years showed that to be the worst decisions I ever made. Desktop quality product in a server box, IMHO.
That was 10 years ago, and nothing in my server room has been HP since. I have had stellar performance from both IBM and Dell equipment over the last decade>.
HP lost me as a customer, basically forever. I won’t even consider their products.
I’m in the opposite side of the house. I’ll swear by HP enterprise-class hardware. I’ve installed and maintained everything from the old Compaq white box dishwashers to the latest ProLiant-class DL and ML line servers and love everything about them: intuitive design, easy installation, great management software and tools.
IBM and Dell were a running joke in our engineering offices. Dell servers are clunky and just try too hard while IBM servers are overpriced for a product that’s more prone to problems than the price dictates. Add on top of that very awkward installation and wasteful “features” (why won’t the damn UID light turn off?!), we always went to HP for our hardware. I still would for server hardware.
Desktop stuff... well I’m a tinkerer and build my own systems from scratch (heavy ASUS/nVidia promoter), so I’ve not played with big name mfg desktops. I’ve had both Dell and HP laptops for work and have had no complaints about either. HP workstations seem to be a little bit more forgiving than Dells in my experience.