I have not not paddled the Vertige but have paddled the Impulse and Eric’s comment about it being a bit of a barge is spot on in my opinion. I believe the Vertige has a reputation as a much better boat.
I somehow happened upon a ridiculous deal early last year and picked up both an Impulse and a Caption in good condition for $125 each (with bags!). Didn’t take long for me to sell the Impulse as I was not impressed with it, but I’ve kept the Caption. I know several people with Mohawk Probes and XL’s and I think they are better than the Impulse as well.