I went through lots of amps and DACs and occasionally had problems with harshness (as you call it, lack of warmth).
Once I siginificantly upgraded my DAC (Chord DAVE) and moved to low power SETs (and I've had several different ones), I've never experieneced harshness or fatigue as I continue to upgrade my system.
I don't think there is such thing as speakers that are "too revealing". Speakers can be harsh but that is just poor implementation (by the manufacturer).
Jerry