The new Boston Valves have been working very well indeed with entirely positive feedback to date. The one observation that I have made is that deflation can be a bit slow when loosening the base out in the surf. The temptation can then be to loosen too much meaning the valve comes out. Not a huge problem but an irritation.
I've come up with a solution though and have had my drill out.
That shot is a super close-up. The residue doesn't affect the thread at all and quickly cleans itself up. Both sides are drilled giving just the right amount of ventilation. The rubber seal of the valve stops any leaks once the valve has been tightened.
All future G-Mats will come with this set-up. Anyone who has Boston Valves which haven't been drilled, feel free to have a go yourselves. If there are any problems then I am more than happy to send over a replacement drilled valve to screw into your mat so give me a shout.