I've only flown the AvGas DA40, not the AvTur DA40D, but I imagine the speeds are pretty similar. There is a huge variation, however, and from memory (hence subject to a few knots error):
Cruise: 130knots
Circuit: 100knots
Base: 70-80knots (*)
Final: 65-75knots (*)
(*) these speeds are scheduled with weight.
Note that the cruise speed is significantly above the typical Cessna circuit speed (the first stage of flap is available at 108knots, full flap at 89knots), and the 'Star is a heck of a handful to slow down in a hurry. so thinking ahead isn't a "nice to have", it is an absolute necessity. Steaming into the circuit at cruise settings WILL result in a very large circuit as you struggle to get the speed off - plan ahead and it's perfectly possible to fit in with a microlight trundling along downwind at 60 knots. We have very few problems at Redhill fitting the 'Star in with other circuit traffic, and I believe this is largely because the instructors make the point well during the conversion training that you MUST fly the circuit at significantly reduced power settings, and that to slow down at all you have to start thinking early.
Now, admittedly the DA40D does have a hugely different engine management technique to the DA40 I'm used to, so the figures may be slightly different, but as the airframe is basically the same, I'd be surprised if there are huge changes.
Having been flying one of the early DA40's for two years, and having got used to the planes reluctance to slow down, it's a lovely aeroplane. Whether I'd really recommend it for ab initio training, well, let's just say I have my doubts. It's a lot of aeroplane, and even when I first started flying it (100 hours) it was almost too much for me to handle. First solo in a Star? My personal advice - as a plain PPL/IMC (no FI or CPL) - stick to the Katana.
Cheers,
MD.