Mine have been brilliant and I got the absolute worst year model Factory 34s there was – 2013.
They 160mm 26 inch. Bike was bought November 2014.
I think they key thing is to look after them really well in the first year. I did follow the 30 hour lower leg service + 1st year service religiously. Since then I’ve let it slip longer and longer.
I got the FIT4 upgrade at a service and added a Push Tune Volume reducer kit air cap. They’ve performed beautifully since then.
I get them a full service once a year with Polished Racing but I do clean around the seals before and after every ride and spray silicone on the stanchions. No hoses involved.
If they’re any year model newer than mine and especially if they’ve already got the FIT4 damper you’ll be pleased. I believe the new 2018 EVOL air side makes them even better though.
I’m hoping to get 36s on the next bike but I’ve not had any issues with the 34s.
I’ve gone over the service interval this year with my riding. They’re due a service soon but you’d never know from their performance or by looking.