ouch wrote:

Does it really give a stiffer rear triangle? I sometimes ride my
brother's hardtail (just for a change). They're different bikes so
obviously it's difficult comparing apples and oranges but his has a
sloping top tube + "shallower" rear triangle. It makes the ride a lot
less stiffer.

Yes - it's a lot smaller and when you're out of the saddle a flexy
seatpost is neither here nor there.