I guess I'm the odd man out here. I've been comparing guitars, new and old, strings, saddle, nuts, -- even bridge pins -- for 40 years, and I have some pretty well formed opinions.
Appreciate it -
1.Old instruments sound better in general than new instruments -- if sound is your thing, buy old.
There is a clear difference. A 20 - 30 - 40 - 50 year old instrument has something indefinable. You feel/hear how much the instrument has come together.
The different pieces of wood really know each other and vibe as a whole.
2.Construction materials (woods) are important -- not necessarily better, but tonally predictably distinctive. Some materials are known to work better for different styles and genres.
Wood is one of the main keys to tonal identity.
3.Top/bracing, bridge, bridge plate geometry -- there are the major determiner for guitar tone.
Be conscious about scalloped or non-scalloped braces and the bracing pattern itself. A long lasting deeply interesting riddle.
4.Setup -- neck pitch, saddle height, etc., etc. Incredibly important-- setup is where the money is to be made. Optimize these, you optimize power.
The right set-up makes you go from struggling over playing to flying.
5.Strings are mostly a matter of taste. I agree that coated strings last longer but lose some power. Once you have the right guitar with the right setup, cheap strings will work fine and will be really hard (impossible?) to beat..
Older strings can like grow to be a part of the guitar as they fade. If that happens, don't change them before they no longer stay in tune.
6.Finally, there is saddle materials, bridge pins, and nut materials. I suppose if you used chewing gum, you might have an effect. What we have found is that the geometry of these are very important -- the materials (within reason) are not.
Bridge-pin and saddle material affects sound. I'm not heavy enough to talk about nuts and bridge plates.
There it is -- sad but true.
What is the sad part. . .
Let's pick,
What key ?
-Tom
E-minor7