Power conditioner some say yes and some say no.

Hello,
First, Do you have the ability to run a new dedicated 20 amp line to you equipment? If you can, please do that first. Also, if you can have the electrician drop in a better grounding rod. 8’ of copper coated grounding rod or two tied together. $20 each is very little to spend for a big change in sound.  The grounding rod that is there might be to inadequate for a music system. It was put their first safety at minimum code. If you did that or cannot do that the I say look into the Puritan line of products. They not only have one of the best power conditioners I have heard but also ways to help fix the grounding by adding a dedicated grounding system and the hardware to easily get it connected to your gear. They have recently come out with a special plug that looks to filter the ground so if you live in an apartment or a shared environment you have a better ground point to feed from. Regardless you should try the Puritan PSM156 power conditioner or double the outlets and filtration the PSM1512. The new product by Puritan is called the Ground Master City. If you live near the Chicagoland area this is the store where I bought my Puritan PSM156. https://holmaudio.com/
They let you try before you buy. No risk to your wallet just your time. Believe me, you will not want to take it out of your system. 

I bought a power conditioner when I go too the point it was a great way to have everything plug into the one unit. I built my own power cords and now it we are going to be gone for any period of time I only unplug the PC. As for improving the sound, I cannot say. YMMV

I say yes and no.

I plug my Primaluna Evo400 right into the wall. It is the only component plugged into that dedicated circuit.

The rest of my components (2 analogue and 2 digital) are plugged into 2 Furman AC-215As. Each Furman has only 2 sockets. One Furman for the digital side and one for analog. The AC-215As are set into a thin hardwood sled that rests nicely behind the rack and below the 2nd dedicated circuit.

Keeping the signal and power cables crossing at 90 degrees eliminated the occasional slight intermittent noise coming from the speakers.

Wall outlets. How charming. 

Seems to me that it would depend on what the needs are. Voltage regulation, DC blockage, filtering of RFI and/or EMI. Conditioners differ in there ability to affect these different issues. There are conditioners, voltage regenerators, and filters. Some use a combination of these. I have no experience with any of the aforementioned devices.

At the moment I plug my Pass XA25 amplifier direct to a dedicated line. My Aric Audio Pre is on a second dedicated line. My digital equipment is on a third separate dedicated line run through a Emotiva CMX2  into a PS Audio Ultimate outlet (a balun transformer). Outlet ->PS UO->CMX2 -> equipment.