I have the
PDW Full Metal Fender City for tires up to 35mm wide. They are very expensive, but work well. Not too heavy at 510 grams. They are very solid and quiet, and never rub the tires. I leave them on the bike all the time now. They work with my 25c or 28c tires, of course, and have enough room for 35c
Clement USH tires.
They are pretty easy to install, with just one stay for each fender and no fussy clips. Locate and crimp the rear brake bridge fitting. Attach the stay clamp and stay onto the fender. Adjust the stay length by a 2mm clamp bolt at the axle fitting. I had to cut the ends of the aluminum stays, they were slightly too long. Oil the stay clamp so it doesn't squeak.
But I had to add an extender for the rear fender's brake bridge mount, it didn't quite reach my bridge, so I made a flat bar aluminum extension (5/8 inch wide flat bar and a stainless M5 bolt and nut at Lowes). And the chainstay bolt didn't quite reach my chainstay bridge, so I got a longer M5 stainless bolt and a nylon tube bushing at the hardware store. ( I have a somewhat non-standard touring/gravel bike, so the bridges might be outside the normal range.)
It's very nice to have fenders for wet roads, like some other comments mentioned. And a tour bike isn't ridden just on tour--tour bikes do local rides, too.
Fenders are great. It's pretty amazing to ride through puddles an inch deep and only get just a few droplet splashes on my shoes. I don't have the "roads are too wet" excuse anymore.
Fender weight for up to 35mm wide tires (at least 45mm wide. The "35mm" fenders are for 25-28c tires.)
510 grams PDW City fenders (measures 45mm wide)
515 grams Planet Bike 45mm Hardcore
630 grams SKS P45 Chromoplastic Longboards