How can a 40 watt amp outshine a 140 watt amp


My query is; I see $6,000 integrated amplifiers with 40 watts per channel, how is this better than my Pionner Elite SC-35 @ 140 watts per channel, what am I going to hear different, with a, let's say Manley Labs - STINGRAY II? I obviously don't understand the basics involved and if someone could explain or point me in the right direction, I would greatly appreciate it.

I would like to set up a nice two channel analog system. I really can't afford the aforementioned Stingray, what is "out there" in the 2.5 grand range?
mystertee
Post removed 
Phaelon: if you can’t hear a difference between amplifiers, then there isn’t any....and you’re deaf! that statement is now getting very tired. Please tell us why no one has passed the test? I am not in anyway saying that when pushing amps towards clipping that the listener will not hear a difference..but at normal levels there just might not be either much or any...I am not running the test. So please contact Richard Clark and try to collect 10k.
Wow, you "guys" rock! I've had a few "duh" moments after reading your responses, of course it makes sense to figure the size of the listening room and speaker type into the equation. Obviously, there are a lot of factors to think about, and I can take everyone's suggestions (which I will do to some extent) but I need to get my butt out to a true audiophile type store to make comparisons based on my own ears. I figured I could surf the net and find out everything I needed to know, I can to some extent, but I have to now do the leg (ear) work. I live near Cleveland OH, I used to go to Audio Craft but they've gone down hill a little (IMHO) if they're still in existence. Bottom line, I've learned that watts is quality not quantity (I think I've mentioned something like that to my wife once or twice, just not about watts) ;) are smiley faces allowed here? I love Griffithds' quote "If the 1st watt doesn't sound good, why would you want 139 more of them!" (first duh moment).

There is so much to learn (crossover considerations, etc) I can see already that this site will help me immensely. Thanks to all who responded, I look forward to additional comments.
It is useless debating the quality of amps alone, they are only heard when they are driving speakers. On speakers that are easy to drive there is less difference, on hard to drive ones more. Don't spend money on things you can't hear; I hear differences IN MY SYSTEM so I have a reasonably expensive amp; my friend drives his Quad 57s with a rebuilt tube Heathkit; they are not sensitive to changes in amps. You pays your money and makes your choice; on some very difficult loads the old Classe 25 watt amp would outdrive amps 10x as powerful, IT ALL DEPENDS!