i still have the original avanti and several sirio vector 4000's, i have been using them for over 20 years, on performance the vector beats the avanti when they are set up correctly ( houres of moving tapping point and retuning for best signal at distance ) but they are way too flimsy to use even in moderate 60mph winds they will break, the avanti was made from infinately better material which with a doubleskinned bottom section withstood 110mph winds that snapped my guys and brought the whole lot down back in the mid eighties, so i hybridised the two to make a 4 legged unit using the avanti vertical extended to 32 feet which lasted a good few years up to the last 90+mph winds when the basket collapsed, another fantastic antenna i had was the ham international big mack,
http://pageperso.aol.fr/daviken/Antennes/Antennes.htm, it outperformed my avanti and would at least equal the hybrid but it too was not really strong enough for our weather, so we cannot forget the i10k, its probably the best performing rugged antenna you can buy today and unlike the avanti and sirio theres no need to spend houres playing with the tuning to get the best signal from it as jay did all that before he marketed the antenna, i have played with mine i just cant stop myself and there seems to be no improvement to be had, you can just follow jays tuning instructions and they work extremely well out the box, its the best of the many 5/8 i ever owned and look unlikely to break in severe weather, if it does break in the wind as opposed to human dammage then i am sure jay will come up with a solution because thats just the way he is, mr avanti, sirio, ham international would never do that, you cant call them up and get advice and they definately did not optimise their product before it hit the market.