Is there such a thing as too much power?

A few more comments:
0. as other have noted, with details your question is academic and no one can explain why. If they try they lie or are fools.
1. more power is better. You may not use it, but occasionally it will allow for un-distorted dynamics etc. And there is  certainly no penalty - with the great, impractical caveat "all things being equal" - since they rarely are.
2. But things are not equal.  Building a powerful amplifier requires money to be spent on things that don't contribute to better sound.  That's the trade-off.  A giant metal chassis, giant transformers, blah blah - that are only useful if you need them. They could have gone into better parts or ????
3. one person wrote: "There are some people who say that using multiple tubes or transistors degrades the sound--simpler is purer." I strongly disagree with this. I have designed lots of amps, preamps, etc. commercially and have never ever heard such, never thought such, and in fact there is plenty of theory that indicates that many devices of ANY KIND in parallel perform better for myriad reasons that would require lots of explanation. resistors' errors average out. Capacitors see lower effective ESR. Transistors non-linearities average out.  In fact i do it all the time, on purpose, even when i could get by with one device. I do it for better sound, and so does Nelson. (he has a power amp with like a billion tiny jfets on the output, all moving about a milliamp in parallel like ants).

All that said, since we are all constrained by size, budget, etc. i have much more freedom to design an awesome 20 wpc amp than if you rally need 200w or 400w.  But only if it needs to be at the same price. My best sounding component set ever is still the same - my lower powered class-A amps run in pairs, fully balanced.  Effortless power.  Just a sense of ease, never straining, never strident.  And since they are fully balanced from the preamp on, quieter and more revealing too.  QED. Same product.  EXACT SAME. More power. better sound.  but, God only knows what it would take to build and sell that complete solution profitably today. Probably in excess of $15k --  maybe $20k. I shudder to think.
So, in theory? No - the opposite.  In reality, quite often the less powerful product can sound better because that was the goal.

The omly important thing for you is that your new amp sounds good and makes you happy.
G

If you don’t have enough power you clip.  When you clip good watts go bad no matter how awesome they were to start with. 

Clipping is hifi public enemy #1 to avoid at all costs.  Wats in reserve are your insurance policy.  Make your amp work too hard and all else is lost. 

Especially tweeters and trashy girfrends.

You can never have too much power. Full stop.

However, do not confuse power with ’loudness’. The latter is measured on a logarithmic scale. That means to get a tone twice as loud, you need 10 times the power (approx). A 100 watt amp is only twice as loud as a 10 watt amp.

However, also note that the supply of an amp, especially how quickly it can source current, almost exclusively determines the impactfulness and the transient response.

A good amp usually has power supply rated at about 2 times the power for class AB and at least 3 times as much for class A (Pass Labs).

In addition, a lower power amp will almost certainly clip much sooner than a higher power amp. So, to get a good higher power amp, its supply must be ready for the instant square wave response.

So in summary.... no you can never have too much power.

It is almost like a car. Would you rather have a 500hp car which you do not stress, or a 150hp car which is almost always working at its limit.

Would you rather have a 500hp car which you do not stress, or a 150hp car which is almost always working at its limit.

Lol! I would rather have a car with superb throttle response.

Awful example. My 1979 Porsche 911SC has only 180 hp and I can assure you it will do 150 mph and is hardly ever working at its limit. Which even if it is, that is what its designed to do! Run flat out! Its just an awful comparison.

I went for a autocross ride one time in a Corvette that had been stripped down, roll-caged, and NASCAR engined to something like 700-800 hp. Who knows maybe 900. Whatever. Instant that car came on the cam both monster fat Hoosier slicks started smoking laying down the biggest fattest burnout stripes you ever saw in your life. The car was all but uncontrollable.

You can never have too much power- if all you want is power. If what you want instead is control, well then its very easy to have too much power. Its all a matter of priorities.