I ride an ISM PL1.1 on my road bike, which is used for everything from crits to long road races. Done rides over 200km with it, no issues. Also done long days in the Alps with it, including >5000m elevation. Very comfortable in the drops, but no issue sitting up for long climbs either.
I do have a fairly aggressive position, spend a lot of time in the drops, and ride TT and triathlon quite a bit. And have had ISM saddles on all my bikes for about a decade (TT bike currently has a PR2.0, my winter/commuter bike has the Prologue which was the predecessor of the PL1.1). My road and TT positions are pretty similar, TT position is just rotated forward around the BB. So I guess I’m both well suited and well adapted to those saddles. If you’re new to that saddle type, or prefer to sit further back on the saddle, it might not work so well for you.