We once looked at a boat with a CAT 3116 and had it surveyed. I know its a different model engine but for comparison we were told by the mechanic it was designed as a 6,000 hour engine, but of course that can be extended with proper care. I think what the limit really means is to expect to do a major overhaul at roughly the expected lifespan of the engine.
High hours also impact resale value, so you can consider this when making your offer because you know if you ever go to resell the boat yourself, potential buyers could be concerned about hours.
Lastly, we found the 3116 to put out noise levels (under way) a bit more than we were looking for, and we ended up not buying.
Again the 3208 could be a different situation and noise is much dependent upon installation, hull design, ER hatch/doors, etc.
(If you haven't done it, i would highly recommend a proper sea trial including a run at WOT)
For what its worth, the mechanic spoke highly of CATs and said he "bleeds yellow".... Best of luck!