I've had a set on for the past 2 years, and with regular cleaning, expect them to last at least that much longer.
Now granted, the ones I got were picked up at a local hot rod/race shop, so they don't have the DOT sticker on them (the only difference between them and the DOT ones is the sticker actually, and there have been no complaints from the state inspectors the 2x it's gone through) they aren't jacketed (why they need to be cleaned frequently) and they did require some AN fittings to adapt to the existing stuff, but then again both fronts with adapters and a bottle of brake fluid came in at under $40, so I consider it a fair exchange.
The feel is a noticable change from even new stock lines with a much more 'connected' feeling when you press the pedal.
I for one won't be going back to rubber lines ever again, and will be doing the clutch soft line in SS come spring.
Besides, they look cool what with the color anodized adapter stuff
