The planet bike fenders I recently installed went on in about 20 minutes with no struggles. All the hardware was included, along with an extra pair of zip ties. The fenders have a limited lifetime warranty to the original owner.

The first pair of fenders I ever installed were zephal. They took about a day and I ended up using zip ties in multiple creative locations. Also, they were harder to adjust.

I haven't tried the SKS fenders, but I doubt they could be any easier to install than the planet bike full fenders. Being German, I expect the SKS fenders to be pretty straight forward to install and good quality. I am very happy with the planet bike full fenders.