It depends on what you mean by a fair amount of power. 0-60 times on new cars with everything to spec were something like 13 seconds. It's normal to not be able to hear the turbo on these cars. Also, when they fail to produce boost, the problem is usually not the turbo itself, but with the plumbing that actuates the wastegate. That looks like a pretty nice car, and based on the information available, I could see myself paying three grand for it. If you get the car and still have doubts about the turbo performance, you can hook up a boost gauge and see what you're getting. Information about getting these cars up to spec abound in the diesel discussion section. Common causes of lack of performance are usually connected to clogged or disconnected ALDA lines, dirty fuel and air filters, plugged fuel tank strainers, lack of valve adjustment, and accelerator or transmission linkage issues. All of these are fairly easy and inexpensive to troubleshoot and repair.

__________________
Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar.

83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 401,xxx miles
08 Suzuki GSX-R600 M4 Slip-on 26,xxx miles
88 Jaguar XJS V12 94,xxx miles. Work in progress.
99 Mazda Miata 183,xxx miles.