Funny you should ask! I just completed installing 2 Fantastic fans. One is a 4000 in the bedroom and a 6600R in the main living area. I looked at both, I liked the feature of the Maxxair that allowed it to be open during rain. I read about everything I could about the two companies and products and determined based on what I read that Fantastic was the product for me. Two factors, first, it's a Made in USA product, second, I did not find a single negative review about their after sales support.
I bought both fans from amazon, they arrived sooner than I expected within 5 days, they where packaged very well to protect them during shipment. The fans arrived without any damage, I tested each one including the remote prior to installation, all features worked as advertised.
As far as installation is concerned, the most difficult and time consuming part was removing all the old sealer. Our unit is brand new and temps in our area are in the 90s so the stuff was really gooey. Fantastic send styrofoam gaskets with the fans, i chose to use butyl tape again based on experienced advise and dealer recommendation. I used Dicor 502 self leveling lap sealer to finish the job. Each fan took about 3hours. Good luck with your project, it will be worth it in the end.