I've found two rules to be very helpful when dealing with this sort of problem;
1. Don't buy it until you need it.
Electronics in general are going to be cheaper, faster, and smaller in the future, so put off all buying of stuff as long as it's reasonable to do so.
2. When you need it, buy it without hesitation.
If the current best solution is X, then pay for X and don't worry about it. Yes, there's a better way, and yes, there's going to be an even better way in the future, and yes X is going to suck in 10 years. But there's no way to avoid that so don't sweat it.
You have Google fiber. You have a 600Mbps solution to connect to that fiber. Do you need more than that, right now?
If not then apply rule 1, and do nothing. If so, then apply rule 2 and wire your house with Cat6 (or pay someone else to do it.)