We actually thought Grizzly was more tame than Kali. We didn't get nearly as soaked even though we did get wet. Without giving any spoilers, some of the effects on Grizzly appear the same as Kali, but are more for looks than wetness.
Grizzly rafts don't have the middle area to keep your stuff dry but there are free lockers outside the que you can use for up to 2 hours. We thought this was a GREAT idea and wish they would bring it to WDW.
We were surprised that the line was only 25 mins long with a fast pass return time of only 30 mins in the future in the heat of the afternoon.