@aphrican

What you call progress has not always been in the direction of aircraft performance.

Much progress has been made in the area of manufacturing cost control, but factory manufactured aircraft have not become more efficient. And liability insurance has killed almost all progress in the US light aircraft industry. This is why you are more likely to find modern concepts coming out of EU.
And now new fuels (that are less efficient), new rules, new safety equipment, etc. is complicating matters. Plus that the modern generation of composite aircraft yet has to prove its efficiency over time.

For real progress you have to look at the homebuilt market. But then you have the problem that those aircraft are not certified for IFR flight or carrying more than two people.

So if we like to fly IFR, we're stuck with proven designs. Not that I mind, because the proven design that I fly is very difficult to beat.

@NazgulAir

Perhaps a Mooney is what I should think about then. They seem to be the only US manufacturer who have tried to continually improve their products in a material way.

The progress made in the last 35 years since my dad's M20F (the plane that he got after his 172) is quite noticeable.

As I mentioned in my OP, one of the compromises is composite versus traditional materials (and fly by wire versus physical connections). I am old fashioned enough that I still prefer natural materials and physical connections. I know a few people who refuse to fly on Airbus products in general and the A380 in particular for this very reason.

As a matter of interest, what is the "proven design" that you fly?

Piper PA-24 Comanche - Wikipedia, the free encyclopedia

Ours is the latest model, a PA-24-260C.
See also here

Have fun reading!

That's not the case. The OP stated that he wanted to fly in the SW USA. You can do that quite legitimately in an IFR 4-place homebuilt. RV10, Glasair, Velocity or Lancair may fit the bill. You can't rent them out to schools or individuals, but there is a significant advantage in being able to fit EFIS and autopilots on the experimental market and also the lower costs of maintenance, parts etc.

With homebuilts now encompassing $1m turboprops, it may be worth considering.