Upgrading wall outlets

Unequivocally, yes.
I've had many of the same others have had: first PS Audio, then FIM 880 (gold and regular), now FIM on one outlet, Oyaide R1 on one and Synergistic Teslaplex on one. All different sounding: I THINK the Teslaplex may actually be the most neutral of them all, but I'm not sure. I'll plug both the integrated and the CD player into the Audience aR2-T (Teflon version, which will tell you everything you ever wanted to know about what your equipment ACTUALLY sounds like without making it sound "bass-ier", "more 3D" "better highs" and the like (although it can do that, but only per recording, not on ALL recordings [which would likely be a coloration, anyway, right?] and then report back. But yes, I had wondered why my highs were softened (pre-Audience, by the way) until I changed to the Oyaide and the lower treble range (trianges, tambourines) reappeared -- without brightness. I belive the FIM has a very slight suckout in that frequency as well as softening transients, although it's quite nice. The PS Audio Power Ports don't have that softening effect at all, but I haven't used them in years, so I'd have to re-install them.
Bottom line? Outlets matter.

No secret that audiohiles are always looking for ways to improve their system, even suttle improvements can be a mile stone to some. I see no problem replacing a standard outlet to one that is upgraded, certainly couldn't hurt anything. I have had a passing thought of upgrading my outlet only because it no longer provides a tight fit for my heavy power cord, maybe the change can also offer a sonic improvement.

A quality aftermarket power cord (I mention this because of its importance in delivering power) can make a slight to huge difference in sound quality depending on the associated gear. As long as the power cord is supplying sufficient amperage the biggest advantage comes from its ability to filter out RFI. This creates a quieter soundstage allowing the finest details to come through.

A dedicated line is also good & I have one using 12/2 Romex. It was already there because I purchased my home from a videophile. On this dedicated line I don't have to worry about induced noises coming from appliance motors and florescent lighting nor brief periods of voltage drops when an appliance initially kicks in.

I just added two 20 amp circuits for my power amps using 10gauge with ground wire. I used Leviton 20A Heavy Duty Outlets. The difference is large. I have blacker back ground and smoother definition. I am also taking all appliances off the electric grid moving them to gas. This will create less demand for amps and to allow my stereo dedicated circuits to breathe more freely.

I have a question about using 30 amp breakers. There are people using 30 amp breakers for there 10 gauge wire and 110 circuits. The only way I know to use a 30 amp breaker and meet code is to use 3 wire instead of 2 and install a 4 plex so each side of the 4 plex is 15 amps. Is there another way to meet code and use a 30 amp breaker? IF you were only going to plug a big amp in would a 20 amp breaker be preferred?

Coxhaus,

If a 20 amp receptacle is used, (NEMA 5-20R), then a 20 amp breaker must be used. The minimum size copper wire would be #12 awg. If #10 awg copper wire is used the breaker still has to be a 20 amp.

If a 15 amp duplex receptacle is used, (NEMA 5-15R), then a 15 or 20 amp breaker can be used. If the branch circuit wire is 14 awg then a 15 amp breaker must be used.

The current carrying guts inside a 15, 20, and 30, amp breaker are the same. Only the trip units are different.

If there is a problem with nuisance tripping caused by inrush current of a power amp most breaker manufactures make a "High Magnetic" type breaker that will allow more lag time before tripping due to high inrush current.

Example:
http://ecatalog.squared.com/fulldetail.cfm?partnumber=QO120HM
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Jim