Quality of tone is kind of a subjective thing. Most people like s-pres high because it strikes a nice balance between low-end thump, smooth midrange, and crispy highs. I tend to find that some of the Guitarhack and JJ Powertube impulses are good for the same reason.
Regarding s-pres high itself, I have no idea if it's available in other versions, but IIRC it was sort of created on a whim with weird settings that happened to sound amazing. That said, the TSE X50 V2 comes with a fantastic IR library with what I think is an s-pres high-influenced impulse called SPH or something like that.
As far as length, some IR loaders (including the X50) give you the ability to play around with the impulse length. I'm not sure which other ones do...Voxengo maybe?
But ultimately I don't really think sample rate or length matter more than at the margins. If you like s-pres high, stick with it.