I just went through this decision process myself, and narrowed it down to the exact same two tubs prior to making a selection. If you like both tubs equally from the wet test, and the dealers are both good, let the features/deal be the deciding factor. Sundance has been around for about the same amount of time as HotSpring (both over 30 years), so quality shouldn't be an issue. I think Sundance reliability came into question just before they were acquired by Jacuzzi, but I have heard nothing but positives as of recent. For me, I was really intrigued by the ACE saltwater system, since I travel fairly often and have a wife who likely would not want to have to mess with chemicals. The Grandee also ended up being less money overall, so that was the direction I went.