As of today, on all machines, gadgets and all that stuff, I think the iMac is still the best hardware I ever gotten myself. It blew me away the first time I unboxed one. Superb design, one cable to plug and you've got a fully functional computer. One cable. I own two of the 2,5k screens one (one thick and one superfine), both with 32go of ram (costed me 200EUR and 250EUR for the ram). The old one at the house, mounted on a wall with a VESA adapter so it doesn't take any room on the desk, looks a bit like magic. I had a shop replaced the optical drive by a big SSD (I tried to do it myself but it's classified as "hard "on iFixit so I failed halfway
The screens are unbeatable. People by expensive screens all the time, yet when they pass by your iMac, they're like "dammit, it looks good". They'll constantly say they couldn't work on a reflective screen and it had never bothered me once.
Love this machine. That's true you can quite easily move it from a place to another with the box but it's not made for that let's be honest. Big and heavy.
But man, how cool is it. Way more comfortable than a laptop to work with. If you're listening to music at a low volume, the sound is neat.
That thing with getting it 32go of ram : do it. Don't buy the ram at Apple unless you don't care about money at all.