I'm the reverse - generally have not heard less sensitive speakers that are any good.

Efficiency is ease of load - sensitivity is the ease related to volume. The former is important for SETs or any low powered amps.

There is usually a give with bass depth - but usually is not always the case - and you gain a ton in the way of dynamics. The slim liners dream about how instruments should actually sound. But even then there are some exceptions - Dynaudio is one.