Boat Cover Material. Top Gun or Aqualon ?

I am looking to get a new boat cover. I have had Top Gun for over 23 years on my last 2 covers. One of the places i went to for estimate recommended Aqualon over Top Gun ? They said it was a better material as long as it was vented which they would install 2 vents using tent poles to keep cover from sagging. my boat is 16 foot Sylvan Pro Select fishing boat. Looking for opinions??

I have a full cover made from Top Gun canvas material. It holds up great short life, my Mako 21 cover is over 5 years old now.

I have a Aqualon cover currently that replaced a Top Gun as well. My boats sit on a lift for 6 - 7  months out of the year. In 4 1/2 years my Aqualon shows no weather wear at all no fading. My Top Gun covers would always shrink just a tad which made snapping and unsnapping difficult to say the least. I less mildew (never had lot my top gun) than I did with my gun as well.  Same size vents in both. I'll defiantly get another Aqualon if I ever need to. I'm guessing this cover will last longer.  

Thanks for responses. I thought Top Gun also. Never heard anything about Aqualon. 

X2 top gun  here 

Top Gun all the way!