I think the longslide actually has a built in advantage over a bunch of other striker fired "competition" guns, in the tremendous amount of metal they left in the tip of the slide...Comparing that to say a Glock LS and its like we've got built in compensator.
I personally like the spring because with all that extra weight on the front, its keeping the recoil on the front half of the gun by not letting it slam to the back as hard as a lighter spring would allow. Add to that the extra bit of force of the slide being thrown back into position...and you've got a gun with a ridiculously low amount of flip straight out of the box. I feel like a different spring would throw off the beautiful balance they've got going for it.
That being said, I'd love a way to get rid of some of that trigger take up... but other than that... the gun...to me...is perfect.