The DS2 isn't a terrible ski, I prefer the Grippers from Polaris over it though. The DS3s are a bit better. I guess it all comes down to what you actually want. You mention flotation, but I would ask what makes you think you want/need more than with the DS2? Many times it comes down to sled setup. Most people that trail ride have lots of front ski pressure, with a setup like this it will never feel like you are floating. For example, I run a Summit 850 with an adjustable limiter strap. When shortened the front end is planted decent enough to get down a trail. When extended, skis only touch the ground when breaks are applied.
Summary of above, if the sled feels heavy in snow; check your setup before dropping $300+ on skis, thinking this will fix the problem.
Reason many of us back country riders change skis is to get better sidehilling. Different profiles will do different things. The DS2 is a junk ski for hard sidehilling. That's where the Gripper comes into play. The DS3 with the RAS 3 front end is a decent setup though.