Is more amp power always better...?

Please don't associate watts with sound quality.    In a 500 wpc amp, if the first watt is crappy, the remaining 499 watts will be crappy.  I have a 40 watt tube integrated amp driving speakers rated at 92 sensitivity.  I can blow the roof off with volume (not important to me).  Most important:  The sound quality takes me places my car can't.

The answer to the title of your post is:  No!

I know this is frustrating but I've found that the manufacture's stated WPC has very little to do with true, usable power output.  One really has to do a deeper dive and either listen in person or get information from a trusted source like an informed friend or dealer.

The simple answer is rarely.  If  you want to seperate  out the real garbage  form the better quality  from a piece  of paper is look on the spec sheet  at the weight.  A friend  years  ago bought a 5x100 watt Sony home theater  receiver  it weight  was less than 5 pounds  it was a gutless horrible thing.  He then got given  to him a old pioneer  receiver  that was 50 watts x 2 and he got something  that had some guts a real power that didn't  blow up all the time it's weight  was around 40 pounds. Better sound. That is a very simple way to make the first cut before  you listen  but if they weight  something  it will be better than a item  that the box and packaging  weights  more than what is inside. A quick way to judge low-fi

I'd say almost always, but too much in excess of necessary may not be needed. 

200-300 watts. For example: MC312