John Albert wrote:

I would never want a single-knob control.

Sounds like you had a cheap, uncontrolled valve. I do like pressure balanced
valves. They strike a reasonable compromise between the cost of a temperature
controlled valve and getting scalded when someone flushes a nearby toilet. Never
seen a PB valve that wasn't single control.

That said, what does annoy me are single knob shower valves that force you to
dial through full cold before they start blending in hot water. Always get hit
with that last little blast of cold water as I turn off the water and exit the
shower. Plus, there is no way to dial back the pressure - it has to be full on
or controlled at the head.