Lots of advice and opinions already given.
Here is my 2 cents worth. Disagree, agree, send me a note telling me I am an idiot it is all good.
This is a false statement - They have one purpose: to reproduce what is given to them accurately. Changing the character of your sound should be done at the preamp level. Enjoy!
I can prove that any day of the week. Not trying to pick on anyone but each component does what it does for a reason.
My company manufacturers tube base products. We have repaired and upgraded all audio products for 30+ years now. In our shop we currently have this month CJ, ARC, VAC, VTL, Marantz, Plinus, Tron, Counterpoint, Prima Luna, Rotel, Cary, on and on. We have heard more equipment that most anyone in various systems. So what I am about to say is based on these experiences.
Most of the input here is from experiences of products that are similar. Designs have not changed much over the years. You are comparing similar products in YOUR own system. That is not the best way to judge a product but rather a good way to select something for your system. What sounds good in your system may not sound the same way in another persons system. Preference is what that is.
In one of our systems we have Vandersteen model Seven speakers. After fixing a Art Audio 28wpc tube integrated power amp, we put that amp in the system to make sure it was working properly. To our surprise, it drove the 83db speakers amazingly well. Who would have thought. I almost kept the amp for that reason alone.
Think of BMW - they make various models and then they offer the M series. What is the difference. Well the M series is an upgrade to the stock model in general terms. Some want that and are willing to pay the price and some aren't. Same goes for audio. In most cases, upgrading an existing component can get you close the the M series without the cost of the M series if you follow me. That is where we come in on repairing and upgrading components. We get to hear the stock versions and the upgraded versions.
So like what has been mentioned already, choice selection is a preference but you can upgrade your component to sound even better for less than you think. You simply don't know what will work unless you hear something in your own system. The goal is to enjoy music in your own system IMO.
Happy Listening.