Check the speeds in your area. I have Spectrum, too, but since Google Fiber isn't near me, they haven't increased their speeds here yet.
I looked into both AT&T and Google fiber, both are not in my area as of yet. I think AT&T is closer, a neighborhood about 2-3 miles away has it. My brother has Spectrum Ultra 300 and his speed test was 334 down and 23 up. He only lives half a mile direct but almost a mile by road. ha ha
The day after I switched from AT&T to Spectrum, AT&T put a notice on my door "AT&T GigaPower coming soon!" I may switch back in a year or so, if Spectrum gives me problems. The 70 or so down is about 3-4 times the speed I was getting from AT&T's old service and I'm paying $20 less per month.
I think the only service that AT&T could offer me was a hot spot and I was like, I could just get that from verizon if I wanted it. Fiber will be nice and I feel like it would be overkill for me!