Is more amp power always better...?

yes

My advice is not to focus exclusively on the watts. A lot of mediocre amps are made to meet a big spec, but not necessarily play well in a system. A better amp and bigger amp aren't necessarily the same thing. All watts are not created equal. You will want an amp that sounds great to you....to do that you’ll need enough clean power to play to the levels you like in your room with your speakers, and that’s always a variable.

I’ve gone the gamut of a big Hafler amp at 255wpc down to a smallish tube amp @ 17wpc triode (on average sensitvity speakers in a large space). I do have a subwoofer, but the main speakers play plenty loud with the small amps, and sound wonderful doing it.

All things being equal, having some power in reserve is a good thing, but power is a poor indicator of how it’ll sound to you. Aim for quality watts with a sufficient power supply and circuit that’ll overcome the obstacles your system poses, hopefully within budget. (used can help cut premium costs down)

 All the specs. of an amp can help determine whether it is a good fit, but in my opinion the signal to noise and wattage will determine your headroom. For dynamic listening you must have headroom and that will take wattage.

How many ohm are the speakers ? 
150-200 wpc is a good average at 8 ohms and she be close to double the power into 4 ohms for any decent quality amp referring to SS .

the reserves are good for transient peaks to prevent distortion if playing loud.

with any room acoustic room panels are a big flus to reduce echo, reflections and distortions.

You want good quality.

This would give you class A power and enough of it. I'd say this would be your amp.