Helix Syn Weight

Having just held each of them... I'd say there's not much of a difference. If I had to guess, I'd say the Syn is lighter... at least it feels subjectively lighter.

@Clenchy Thanks for your response. Would you say the Syn response is different to that of the classic?

Yeah it's certainly a different beast, for better or worse. Apparently it's a slightly different shape from the classic, but most of what I notice about it is the softer touch it has, as well as the much more springy/weak p-tab. I've had really good sessions with it, but I'm not sure how much I like it overall.

At the end of the day, they're all just tools. And as your rewiring changes/develops, different models can surprise you. I think every model I have has spent time as my most and least favorite at some point. Because maybe you start noticing a nice feeling in a new spot, and it just so happens that one of the models you got nothing from a few months ago, turns out to hit that spot nicely.
Which is why I find it hard to make absolute statements about how a model performs.

My experience is "spot-on" with all that @Clenchy said. Just for grins I weighed them each on a Postal scale. Classic came in at 1.36 oz and the -syn was 1.25 oz. On a lab balance the Classic was clearly the heavier of the two. Neither had a recent run thru the dishwasher but the -syn looked scum-free. My -syn is an early production sample and it has the 'twisting' p-tab. Being a 'firm-tab junkie' I prefer the Classic. OTOH the -syn makes for a nice ride when you want several hours between lube jobs.

Thank you both for your input.