Mine is almost a year old and all my knobs are fine. Push button switches are fine too, but I've had them fail on other gear, and even on my Keurig coffee maker. Any mechanical switch will fail eventually; it just depends on how much it gets used.
If/when your OB6 is out of warranty, you could try to replace the pots and/or pushbuttons yourself, if you're any good working with circuit boards. It's just a matter of unsoldering the old and soldering in the new. You WILL need a decent soldering iron (forget that Radio Shack garbage iron and buy/borrow a temp controlled soldering station, like Weller. Buy some soldering wicks to remove the old solder (works way better than those suction bulbs.)
You can then use your soldering skills to make your own audio cables, buying a roll of Mogami cable (the best) and good quality connectors. I bought a 50' roll of W2524 for about $1/ft off Amazon, but before chopping it up I installed a Guitar plug on each end and plugged my guitar into my Fender amp. No hum or any noise at all with the amp turned up to 'patent pending,' (an old ZZ Top line.) I was tempted to leave it at 50' should the occasion arise for such a long length.
Mogami makes the best cable ever, and is priced accordingly. Just look at the price of their premade cables; $8-$10 per foot.