Don't knock the SLR saddle if you've never ridden one.

Especially if you own a Brooks.

There isn't much difference between an SLR and a Brooks -- the Brooks is just as thin, if not thinner than an SLR (remember, the Brooks is just the leather over the rails).

Thus, if you love a Brooks, you'd love an SLR. I've ridden both (and ride SLR's) and they both feel very very similar.