Quite the contrary, it's with the vast amount of knowledge I've gained that I've learned how serious these factors limit single driver speakers.
DGO,
I really hate to push back but I have to step in and say something. Granted, the speakers that you have experience with didn't trip your trigger, but that does not mean that others can't fill (nearly) the entire audio spectrum quite well. Your comments that a full range driver can't do it all is only do to your specific experience with the few speakers you've had exposure to.
ScottF,
No worries here man, I enjoy hearing other's experiences. I enjoy dialogue. That's what I love about this place. You have to keep in mind I come from a different background than most audiophiles. The same limitations I describe in single drivers being asked to multitask over a wide frequency range, are the same problems that exist in microphones. Condensor mic's come with very small to quite large diaphrams, and with that, there are strengths and weaknesses to both. Speakers are essentially the reverse to a microphone (albeit more akin to a dynamic mic vs a condensor).
Can a single speaker go down to 30 Hz and up to 12 Khz at the same time? I'm sure it can. Can it sound good doing it? There's enough people who have heard them, that have lots of experience with gear who say yes.
But do I think that a really high end single driver can cover a full bandwidth range, playing very dynamic and harmonically complex music, without distortion ,strain and compression in the way a multiple driver speaker can (say, a line array)and sound as full and harmonically rich doing it? I haven't heard it yet. Nor do I think it's physically possible.
Electrostatics, planar speakers, or ribbon speakers, I don't have as much experience with so I can't really say much. I'm strickly talking conventional cone type drivers and conventional tweeters ( Dome, ribbon, planar)
I realize that debating this could irk someone who believes his choices (be it 2 ways, single drivers etc,) could take my comments personally, but that's not the intent with what I'm saying. My posts are strictly for posterity, and general discussion of audio, and the technologies that exist in an effort to reproduce sound.
Problem is, is that with every move I've made, I get closer and closer to the realization that line arrays are probably as close to ideal as possible. I'm up to a 4 way speaker system now, and still own a number of 2 ways and when I go back, it's always a shock. I can't go back now. I'm just missing too much. Dynamics, clarity, articulation, resolution, impact, and frequency range.
Does that mean that other systems can't sound absolutely wonderful and engaging? Hell no.
I'm really looking forward to RMAF. Looking forward to hearing all the gear, and meeting AudioCircle regulars.

Oh, and too add to T 37's list of speakers to check out. He should look at RAW Acoustics HT 3's, as well as the OBX offerings. The GR Research A/V 3's are a great T/L MTM 2 way, and the OB 5 and 7 series speakers are simply amazing. These are offered as DIY kits and offer some of the greatest value to the budget conscious audiophile. All within his budget as well.
Cheers