in my long experience with volume pedals I have learned that very, very few products are consistently good. The problem is always the internal potentiometer.
Very often the quality is poor and the pot is dirty. Some incorrect electrical contact happens then and cleaning with contact cleaners may often help.
The taper is another story. I find the Ernie Ball pedals to be more progressive than others.
In general I prefer to test pedals before buying them. Some people have the pots changed in any pedal, referring to qualified audio technicians who have quality parts to substitute in the pedals.
The electrical specs for the pots are the ones you find in the manual. The taper is a very personal thing. Only trying different pots will give you the idea and the feel of what you'll like best.