Right then, I've not had a chance to test it out properly yet as I was marshalling but I have put a couple of pots of old (really old) blaze, and a pot of hellfire through it over the chrony.
Test done with a push button matrix, trinity, bolt kit & gun20 chip, 14" powerlyte kit using .688 for the blaze & .686 for the helfire.
The blaze was firing 289 +/- 5fps consistantly, the hellfire shot @
295 +/- 3fps.
No breaks (seems obvious but best to say)
On first impressions I like it, the inserts are approx 6", the machining quality is excellent and the 'compression' fit on the inserts is a great idea.
I've not had a chance to try it out on the field or over any decent distance but I'll keep you posted.