Rockshox did certainly have a problem a few years ago with their anodising wearing off the stanchions on their forks - this was mostly due to inferior seals being used. I also had this problem which meant a new CSU from Canada for about £120. For me it was most likely made worse due to not servicing the forks for over 12 months despite them being ridden in all weathers (this was on an off road MTB which got abused all the time) Rockshox then changed to better stanchion seals. Rockshox advise that their forks are serviced at least every 6 months.
As to Suntour, their forks are OK if you do light riding and are prepared to dismantle them more often than most other forks. Compared to Rockshox forks in a similar price range (e.g Epicon compared with the Rockshox XC series), Rockshox wins for durability, servicing and spares. It's unusual to hear that a SID seal kit was not readily available for a rear shock. As I do not own a bike with a rear shock I don't know much about spares for these things. If price were no problem I would always go for Fox forks. Until Suntour sort out the spares problem I wouldn't be putting them on my top choice list. That said, their Epicon fork seems like it could be a good bet if spares were readily available. If you look at the professional mountain bike teams hardly any of them use Suntour - it's either Fox or Rockshox. Ok, you might say this is due to sponsorship and other financial deals but you could also say its because they work consistently better than Suntour and are time tested.
