They were either trolling, ignorant, or unimaginative. The imac is pretty iconic, but it's obvious that others can design their own thing. The HP looks like it took real design time.
They use a very good display panel. I don't recall a terrible number of dithering issues. Apple always used a slightly non standard color temperature setting, but it wasn't too bad. LED backlighting causes some profiling issues with typical off the shelf colorimeters. They mostly compensate with device LUTs which isn't a perfect solution, and
I bought my MBP in 2008, the only Apple machine prior to that was a Mac Plus. So you can see a significant spread there. Unfortunately that Mac Plus taught me a few lessons about all in ones, even though I really loved that machine I've resisted such on the desktop since.
You say that but yet they did just that on their laptops. Compare any of the MBP to laptops prior to 2008. Now maybe serviceability and general access wasn't their goal but the end result is notable.
I'm not sure what the net effect is here. It's unappealing to me given some of the longer term issues I've seen with the imac lineup. Obviously mac sales have been dwarfed by their idevices. There are other things that strike me as weird, like the lack of an included keyboard and mouse with the mini.
AMD has been improving it since they bought ATI. You might see some AMD options show up there too. They're using mobile workstation firmware cards for heat reasons in the thing as their upgrade options (I think default is integrated graphics). I don't know what AMD has coming up in mobile firepro cards. Given that they're using mobile cards, it would make sense to wait for kepler quadro m cards, which will probably show up later. Then of course you want to know that there aren't any terrible bugs with the software you use.
This is the type of product Apple used to be known for, features that actually make it easier for the owner/user. Options and an easy to open case. Today Apple only cares about "the look" and has taken it so far that Apple is removing features from its computers. The Z1 is the iMac I could see my self owning if there is a matte screen option.
In my opinion Apple just got its "design ass" handed to them on a platter. Apple used to be known for innovation. Who ever thought HP would trump Apple?
They have quite a few display options. Height adjustability is great, and it's one of the things lacking in the imac stand. I'm not sure how they'd maintain balance with a small chin. Most displays use a weighted base with a spring loaded telescopic base for height adjustment. HP seems kind of hit and miss in terms of reliability. Their dreamcolor displays are nice, but quite expensive. Even there, I've read complaints about dithering issues, so I definitely wouldn't go for the first one off the line.
Amusingly you mention this a lot on hardware options as if you were expecting new cpus long ago. I'm guessing you haven't updated in several cycles if you're that worried about a new one?