I finally got my new umbrellas from CushionsAndUmbrellas and I am so impressed with the collar-tilt function. Sunbrella fabric and the tilt collar was a draw, plus these umbrellas have double venting so winds should not bother them much if at all in spite of the huge size. We have set-in sleeves on either side of the spa and so we got two 11' umbrellas to shade that area for the new grandbaby.
I have been getting bargain umbrellas from Amazon ($65 - $100) when I see on with fiberglass ribs, aluminum pole, and a color that I want. They all had polyester fabric and the oldest is starting to fade a bit in its second year. The $100 one by TropiShade is 11' and very lightweight, no tilt (no longer available, drat). The 9' umbrellas were tough to right after tilting, even though they have fiberglass ribs also. So I bit the bullet and special ordered 11' umbrellas with Sunbrella fabric and the collar tilt mechanism (about $320 each, Sunbrella fabric was a lot of the price).
Wow, that tilt feature is slick; crank open the umbrella, then twist the collar above the crank to tilt. Effortless, any degree of tilt you want to about 45 degrees. Goes back up just as easy as it tilts. Made by California Umbrellas, sold by Cushions And Umbrellas. Warning, special ordering was not fast, apparently the factory was backlogged and the seller comped me 5% for the massive delay, on top of coupon online.