I have not ridden a 1000ds engined bike, only 800's and 900's, so I cannot give you an absolute comment. What I've been told is that the 1000ds engine is an awesome unit, and will definitely pull harder than the 800. But then again, the 800 is an awesome powerplant too!
You may want to look at Brad Black's comparison here.
Have a look at his other tech notes as well. You will see that there are a lot of factors that combine to give the riding experience, including engine modifications such as pipes, free flowing airbox and fueling mods such as the Power Commander and Rapid Bikes. And then factor in gearing - I've changed to a 14T front sprocket and it is a whole new bike..... All this makes it a hard comparison to make, and a very subjective one.....
I Can tell you from my experience that my M800 has way more power than I can safely handle on the road. I have never has a situation where I've thought, "if only I'd had some more horses" - well maybe once or twice trying to chase my fellow DMLers on their higher powered 2 and 4 valvers on a straight! But really, those times are few and far between.. I have not taken it to the track, so maybe I'll find the limit there, though I know that I'll find MY limits before the bikes, track or street..