Look at it this way, one way or another, tube or SS you have to produce the same amount of voltage and current through a speaker to get the same volume.
Whatever theories there are about a conditioner limiting current you are going to have exactly the same issue no matter what.
The physics say that to maintain current you must maintain voltage, so a power conditioner with built in voltage regulation like a Furman AR series unit is the way to go if you want rock solid voltage year in year out at all times of day regardless of your AC running or not. The next step up from that would be a PS Audio power plant.