i actually got the shock on ebay from white2505 on here, once he realised we were both forum members he through in the red spring as well (as it wasn't part of the auction) decent chap, he had already converted it for the 3tj with the bottom fixing extension and the black spring.
i think the red R6 spring is about 520lb spring rate, the standard 3tj spring is only about 325lb and the black spring is 395lb which is pretty good i must admit,
the original was shot and actually rubbing the rear hugger with just me on board and taking a pillion was out of the question it wallowed about all over the place, now it's planted, 3 up on the pre-load is quite stiff enough for me (14.5st) and another couple with pillion,
from what i can gather most peeps put the 395lb spring on as the red is, as your finding, way to stiff for what passes as highways, if the roads get much better we'll all be riding Xers