I just bought the Soul. I was actually waiting for the SurfDry 3.0, but it didn't come out this year and I needed a suit so the Soul was it. I know OR makes a quality product and puts a lot of time into the specific design needs of kiteboarders. I also heard good things from local riders who own it.
I did consider the neoprene dry suits as well...Ion makes one, Mystic makes one, and some others. Have you picked one up? They are really heavy. Try it on. I'm told they don't breathe...so if you sweat, you're getting wet. They do seem like they would be great on a bitter cold day and to be honest I've never kited in one, but it wasn't for me. I have a 5/3 wetsuit that takes me down into the high 40/low 50 F temps and then I go to the drysuit.
I only have one session in the Soul but so far I'm impressed. It was a 32 degree F day...cold! It is very light. I have had a traditional baggy before, and the Soul is much more form fitting. I was surprised as I have seen some of the pants/jacket looking dry suits that appear like there is just too much material, but you put the Soul on and it is just right. The pee zip is clutch...I have dealt without it for years, but honestly, I usually have to take a leak right before I get on the water and again after a long session. It is so nice to not have to pull the entire suit off when you have other outdoor rigging/de-rigging to attend to.
The dry suit did seem to breathe for me. I've learned to not layer up too much under any drysuits or you will get hot. I had mild dampness around the ankles after a 90 minute session. I've never been able to avoid that on any suit. The "stand-by" mode on the Soul is also pretty cool. I can actually put my drysuit on at home, drive to the beach and rig up with my coat zipped up, but still getting plenty of airflow...so I don't feel like I'm all suited up. Then you just slide over the neck seal, zip up, and you're good to go.
Anyway, that's the first impression. If it changes after a few sessions I'll update this.
I also really liked this kayaking drysuit
. Only reason I passed is I wasn't sure if the zipper across the chest would chafe with a harness over it. They have a model one up (Double D) though with a back zip that is on sale now for less than the arch rival.