Some of the Swarovski Z8 have plastic turrets. Never heard of plastic components inside. They made scopes for the German military starting in 1949… so…They are not as heavy duty as NF but arguably have the best glass available and don't weigh near as much. I have used them for many years and have never had reliability issues. Bouncing around on ATV's or in trucks no issues.
Everybody has an opinion on who builds the best scope. I like Swarovski because of the quality of glass, Some like NF, some like Leupold, some like Schmidt & Bender, some like Zeiss, some like Japanese glass…it's usually a matter of opinion and budget.