Like you say Rob, there are countless choices regarding the 6600R-417 fans. I just got off the phone with the tech people at Fantastic Fans. These folks are great. They basically told me I had at least three options, none of which requires me to buy a whole new fan to upgrade my current stock fan to a 6600R-417. For around $100.00 bucks I can buy the upgrade kit. Buying a whole new unit would cost me a minimum of $242.99.....(best price I have found on-line for a 6600R-417). Since I can reach my current fan from the bed area I don't think I will go with the remote. (although, being a guy, I may have to have just because) Other than the remote I will get all of the same bells and whistles of the 6600R. The main thing I am interested in is the rain sensor closure system. With the sudden downpours common in Colorado, I see this as a good thing. Plus, the upgrade will also work on a thermostat, so when it gets too warm in the camper for fido when I am not there, it will also open and turn on automatically. The other nice thing about the upgrade kit is all of the changes are done from the inside. No need get up on the roof to make any changes. The folks at Fantastic Fans gave me several options and basically could have sold me a new fan but instead, talked me out spending more than I needed to spend, based on my needs. Nice to see that type of service still out there!
Just in case others are confused with all of the options available.
Good Camping,
Paul