I have a Reactolite inner fitted to one of my Corsair visors, and although it does an excellent job of preventing fogging up (which the Arai is particularly prone to ), it has the following not so desirable attributes:
1) It adds £30 to the cost of the plain visor giving an all-up investment of approximately £65 and as it is non-transferrable - you will have to ditch the whole assembly if you scratch the visor sufficiently badly.
2) If you bend the visor far from its natural curve-form - the inner will detach from the visor in places. This happens quite easily if you carry the visor in a belt-holder around your waist (especially if you are a porker )
3) I never found the photochromatic effect to be much good, to be honest (someone did advise that it reacted to UV light and the Arai visor was already filtering a lot of that out? )
It looks better in use than a Pinlock insert, but for cost and maintenance - it loses out to the Pinlock.
word of warning the new universal fog city is rubbish...........they have used a new kind of glue and they don't stay in place...........i had the old type hypo ones and they were brill.....got a couple left, but the new ones are rubbish save ya money and get a pin lock....u can get a light/dark tint..and they stay in place......... www.racevisors.co.uk