If cared for 3500 hours should be considered a mid time engine
Nothing wrong with turbo's, but they are something else to break, more complex than a NA engine, but more HP, smaller and more efficient engine for the HP
Just as a bit of anecdotal data I'll add that I have 6,568 hrs. and 15 minutes on my naturally aspirated 4JH3E Yanmar with no indications of any real problems to date. I did replace the oil cooler a couple thousand hours back and I have gone through three temperature sensors, but no other significant parts.