Fiber Modems - repeated hardware failures. . ??

We got Gigablast a few months back - replacing the traditional cable modem with a fiber modem and router. HOWEVER, we have had multiple issues where the Fiber Modem just goes "down" - and can't be fixed. According to the tech who was out to fix it, this is a hardware issue with the fiber modems - if you reset power to them, 50% of the time they just go down and have to be replaced.

Are other people having this issue?

Cox is coming out fast, usually within 24-48 hours - but it's very problematic when it happens ever 3-4 weeks. . . what is the point of gigablast if we are losing service that often? i'm considering going back instead to old style cable modem with slower speeds - but at least more reliable service that can actually be replaced without waiting for a tech every time it goes down.

Would appreciate any feedback especially from Cox.

We live in Phoenix, zip code 85254.

Thanks,
Alex