Can a Quality Full Range Speaker be the Limiting Component in a system?

@douglas_schroeder   Doug, appreciate your post. Points well taken. 

How would you re-state the question or problem?

My only experience with a "full range" single driver speaker was the Hornshoppe Horns. Within it's operating range it was really nice. 
Sometimes wonderful.
That's the problem. 

All the best,
Nonoise

In my experience the answer is "unlikely". Assuming the speaker is not fatally flawed in some way my experience is that upgrading the source makes the speaker sound better. I currently have a mid six figures system in which the speaker is less than 10% of the system cost yet every time I upgrade a piece of the system the speaker sounds better. No doubt a more expensive speaker could sound better but it would need re-optimizing the entire system around it. System synergy is the key and I would suspect that unless and until the room changes (bigger for example) a well matched speaker still has a lot more to give

My experience is the same. Unless there is a big room change or you want a very different sound or start listening to the kind of music that your speakers are not up to, orchestra music as an example, good speakers don’t need to be replaced.

Yes, a full range speaker, even if matched to the room and amp, can become the bottleneck, but it usually isn't.

I have been building speakers for 30 years and am a former industry member, so...

Most competently made speakers of a given size are going to work as they were intended, and the botteneck will occur elsewhere. Except in the following case:

The speaker has limited dynamic range for the kind of music and SPL you like.   Many speakers which sound fine on jazz and rock at medium levels, fail to reproduce full range orchestral music, which can have almost 30 dB peaks.

Orchestral peaks sound hard or distorted, or the woofer does not reproduce the bass tones and pitch correctly (one note bass).

Even on jazz and rock, the increased dynamic capability increases the emotional content, imo.

This is why I stick to large, sealed box woofers (10 inches or more) and multiple midranges if needed.