It's a tough one. I remember being very impressed with the stiffness of the Levelboss 1030 when it came out. It felt like it was an extension of your spine, a kind of precision tool. Before that, all we had were Montys.
On the other hand, I rode a Triton for almost 2 years and got very used to the springyness of the frame. It really did make a difference.
I sold the frame on last year and had the chance to ride it this year when I met it's new owner. Getting on it after riding a Gu Le BB40 for a few months was a sensational experience. Despite my GU weighing in at 8.6kg and that Triton build being around 9.5, it felt as if I got a massive boost of energy. It's really difficult to describe but every little hop on that frame felt light.
The nature of the springyness of Tritons (at least mine) was that it felt very rigid but delivered a small kick out of nowhere. A sensational feeling if you're not used to it and also difficult to describe.
On that basis I'm a big fan of springy frames but it's got to be done right. A 221 X-Lite I had in the past where the seat tube broke off the BB might have had a good 20mm of travel under hard preload but wasn't the kind of springyness one was looking for.