What makes the Model M so good?

Why does everyone say this? I might buy one from Unicomp, but what makes them awesome?

Just the typing experience. You can't beat a buckling spring keyboard for typing. It is lovely. Plus they make an amazing clicky sound.

That and they are built like tanks.

Did I mention that clicky sound?

Built like a tank. Not a fan myself.  

Do buckling springs feel like Blue Switches?

80's nostalgia?

A bit. They are a little heavier. More inline with the CherryMX Greens. 

Really though nothing feels 100% like a buckling spring Model M.

They feel like a blue but with a much more noticeable click.

I've typed on blue, brown, and black cherry switches as well as a handful of alps. I still prefer typing on the M.

I also find it great for gaming.

Not so good if you have roommates or are in a cubicle, but whatever.

Here's mine:

Was originally the ugly puke tan. Dyed the frame black (with many, many tries. Tough plastic) and sprayed the keys with a vinyl matte grey. I sprayed many coats lightly from far away to give the keys a distinct texture, and after a few coats, I then applied a low-gloss clear coat.

The result is each key feels like the texture of a playstation's analog stick. It's quite nice. 

The reliability. I have a Model M from 1989 and it still works just as good as it did then today.

To the feel, I would say they are like heavier than greens. As greens take 80nm of actuation, I'd say the Model M buckling springs are about 110, well on my one anyway. I've heard that the newer ones are slightly lighter.

That is a lot of force. I am on MX Reds right now. That will take some serious adjusting