I disagree. Look at the Deere 3320 and the 3520. The 3520 is a turbo with a smaller size engine, more hp and more parts. When you run smaller engines with greater hp engine life drops, now add more parts and you have more things that can fail regardless how "pretty trouble free" they are. they can not be as trouble free as the engine without them.
Even if you look at Wikipedia's article on turbos it talks about reliability, again, granted diesel's aren't as prone as gas engines but they still are more prone to failures, high heat and parts problems than non-turbo engines.
If you look at Deere's "engine operation" in their manual you'll see that they recommend idling for two minutes after hard use for both engines. That's because heat build up is bad. Which engine do you think runs hotter all day long when you're pushing it? Has to be the turbo with hot air constantly being rammed into the intake manifold.
Now add the turbo whine and tell what you're getting for the extra few hp?
I just checked Deere's fuel comsumption specs on the 3320 and the 3520. The 3520 is listed at 2.4 gph and the 3320 at 2.0 gph. So according to them the 3520 also uses more fuel. All this for 4 more hp, not worth it for me.
Rob