Pull the other one it's got bells on it!
With a Zodiac PVC sib, then 10-15 years before you start to see seam play, etc. A lot if this is usage, weather and ambient operating temperature, build from bag or inflated all year round. Hypalon, then 15-20+years, again same factors apply.
Grand Raid hypalon boats are great. They are repairable with plenty preparation. Check out Polymarine's site.
Your post has given me a thought for a thread!