Anybody used this? Nikwax are touting a new and improved formula, so wondering whether it’s worth a go. Presuming it gives water resistance similar to Epic, but is it durable?

I didn’t find it as good as Epic to be honest. It’s okay and significantly better than untreated cotton if you’re caught out in a shower, but don’t expect miracles would be my advice. You also need to factor in that once it’s treated, to maintain performance you’re going to have to wash in tech wash or pure soap – which is a pig to find, the latter that is or expensive, the former – and/or re-proof. Epic, which is silicone encapsulation, is more durable I think.