I have little experience with foam tips. The first I had were also Comply, coming with my earphones. Then I had another pair, of which I don't remember the brand. I wanted to try something cheaper (about 40% cheaper). So this review has not much of a base.
Comply seems to have a good quality control (all pieces are well formed and well fitting), and the foam really has "memory": when squeezed, it takes a few seconds before to come back to the original shape, so there is time to put it in the ear. The other tips I tried were going back to the original shape instantly, so the insertion in the ear was a bit uncomfortable.
Also the sound insulation seems to be better.
For the lasting, I didn't notice a great difference.
To me, they are worth the little extra cost.
A note in general on foam tips. I never felt comfortable with silicone tips, also because my ear canals seems to be different; what somehow fits in the right ear doesn't fit in the left ear. But even with different tips for left and right ear (my earphones came with 9 different types, and I tried them all), it always felt like going for the lesser annoyance.
With the foam tips, in the worst case, I went for the lesser satisfaction.