Darren,
The best and safest fix if wet sumping bothers you is to put an on-off valve in parallel with the anti-sumping valve - that way the valve is just a fail-safe in case you forget to turn the valve on.
I can confirm that anti-sumping valves fail - I was on the M62 heading to Hull for the John Bull Rally in Belgium, following a mate on his Y13 750 v-twin. He suddenly had no oil pressure. We cut the valve out on the hard shoulder, resulting in a big pool of oil (not too proud of that) and so fixed it, luckily no permanent damage, largely due to non shell bearings.
Cheers,
Ted