For example: Payne or Armstrong compared to Carrier & Lennox.

I've read that the lower-level systems (for the most part) have yesterday's technology. Now its seems to this novice, that yesterday's technology MAYBE more proven than the cutting-edge systems on the market today.
Of course, all systems carry a warranty, so that's not a concern, but what is, is downtime in the middle of a heatwave if I do going w/the cutting edge product.

My wife is a teacher, and she has a Payne installed and shared between 2 rooms. Crappy install but it still been reliable over the years. Before that, she was in a different room, and had bleeding-edge tech Lennox installed and there seemed to always be issues.

So in a nutshell, I'm asking isn't yesterdays (proven) tech more reliable than today's High-eff, cutting-edge tech?