"Blued steel springs make the action feel much snappier, whereas stainless steel can make it feel sluggish."
I don't think this has much to do whether the springs are steel or stainless. Kraus unpointed stainless steel springs perform every bit as well as steel springs.
Kraus versus Ferrees stainless steel probably has a bit to with the actual alloy of stainless steel used, and how polished the surface is. In general, stainless steel makes a poor bearing surface, but higher grades (eg what Kraus sells) are similar to steel.
"Don't have blunt ends on the springs"
I find that blunt ends can be fine. Without going into a long technical dissertation, friction associated with blunt ends is more to do with the shape of the spring cradle, the surface finish of the spring, and the direction in which the spring is tensioned.
For minimum friction, a spring/cradle combination ideally needs to be set up so that there is a rolling action of the spring in the cradle, rather than a sliding action. It so happens that if other factors are not good, this rolling action is sometimes more likely to occur with a pointed spring.
So in this sense, I concede that pointing a spring can be a form of band-aid. At the same time, I think that the reason why springs were originally pointed is only that they came from a needle-making factory.
On the very highest quality flutes, where players are obsessed with the 'feel' (and spending money!!), white gold springs are used. They are never pointed, and are actually quite thick (because gold is a poor spring material!) The feel is excellent.
Sluggish 'feel' is most often to do with the diameter-to-length ratio of a spring (and that is to do with diameter towards the mounted end, not the 'cradle' end. The larger this ratio is, the more the finger force needs to increase during the travel of the spring, which translates to 'sluggish feel'.
Getting this ratio low, while getting sufficient force from the spring, has many repercussions in the design of the sax, eg the location of posts, and few sax makers seem to attend to it well. A Mark VI has a good feel because Selmer must have had a good designer once. That guy has probably now been replaced with a bean counter.:twisted: