[ecomodded]

I shift at 1500 rpm usually, 17- 1800 rpm if i need to step on it.
In town i use 5th gear starting at 50 kmh or 30 mph, the motor stumbles at about 40kmh in 5th so I get away with cruising in town using 5th gear 30 mph at 1000 rpm.
I put a cheapo 60 dollar ebay fuel pump tuning box on my tdi and gained a ton of low speed torque, which makes driving in 5th at 1000 rpm a breeze.
My motor is the AGR 1.9 tdi with the ko3 waste gated turbo.
The people saying to shift at 2500 to 3000 rpm must have a need for speed or are under the false ideology
that they must race their motor before they shift or else like you suggested will break the turbo.
I have heard people saying that you should shift at your peak hp rpm's or else you lose economy(hogwash) they reason that your car is at peak efficiency while in your peak hp rpm. That is simply untrue, the lower the rpm the better your fuel economy, i say that from my personal experience as well as others.
I bet you would blow your turbo from years and years of high revs, not by babying it, its the design of the vnt turbo that causes frozen fins.