While I had an IBM Model M as a kid, and used it extensively, I do not miss it. The keyboard was unbreakable and built to standards we can only dream of today (that part I miss), but the actual tactile experience of the buckling springs is somewhat overrated in my opinion. I recall mine requiring pretty heavy presses and I, from today's perspective, don't appreciate the actual sensation of feeling the spring collapse under my fingertips. It was somewhat too sharp to be pleasant.
Great keyboard, just not the pinnacle of typing experience it's sometimes presented as.