In reply to The Pylon King: It's quite hard to describe the difficulty of highballs using the various grading systems on offer (not that I'm suggesting we have an H-grade). I like what the BMC guides are doing, giving both in various combinations of brackets.
The thing that bothers me is:
a) flashing a strenuous sit-start lowball V3 and thinking "that has added next to nothing to my experience of climbing" and then
b)slapping, heart-in-mouth, for the top of a sustained, teetery highball V3 with a slightly iffy landing, and thinking "oh my god, that was an incredible experience I will never forget"
and being told that these are "worth" the same in terms of difficulty. Highball V3 can't generally be climbed by anyone with a lowball bouldering limit of V3. How many V3 boulderers who have never led an E1 would get up Pig's Ear or DIY, for example?
Equally, onsighting a proper E3 is much different to bouldering out a highball, falling/jumping off onto pads from gradually higher up until you eventually get to the top.
So, in answer to the orginal question, I support "E1 6a (highball V3)".
Or we could just go back to how it used to be, and grade every single one HVS 5c regardless of difficulty (more Stanage examples: Not to be taken away, Love Handles, DIY, Mating Toads, etc etc).
P.S. If anyone would like to tell to try climbing somewhere else other than Stanage, I tried the other day at Slipstones, but it was covered in snow.