I'd agree. I can't see the diagram, but even if you upgraded to the AC66u I doubt you'd see more than 600Mbps or so with a pair of them in bridge mode. So you aren't going to be getting nearly the 1Gbps fiber speeds you'd be paying for.
Are there no intermediate packages to save yourself some money? Or wiring it?
I'd find out what kind of WAN you are hooked up to. DHCP/WAN you can look at the smallnetbuilder WAN test numbers, but a lot of fiber is PPPoE, and that is generally around 30-80% of DHCP/WAN numbers because of the overhead with header compression involved in PPPoE. Apparently TP-Link routers are supposedly very good at PPPoE and a number of others, like Asus routers, are terrible at PPPoE.
In either scenario, even DHCP/WAN, unless you are buying enterprise class routers, you probably are not going to get full 1Gbps speeds paying for 1Gbps fiber. You'll probably get more like 600-850Mbps, depending on the router, and probably more like 200-750Mbps if it is PPPoE...dependent heavily upon router selection (which is hard to do as few test PPPoE).
Now...obviously if it is real cheap to pay for 1Gbps I'd go with it...but is there any real reason to? Maybe I am used to my crippled internet connection here, but with my 75/35 connection, I'd say I am lucky if 1 in 4 connections can actually push my 75Mbps downstream connection to the max (actually, its a hair over 80Mbps in reality, but I won't complain). I'd imagine at 150Mbps even fewer connections could make it sweat.
Again...poor market...my 75/35 (for the US) is fairly cheap at only $70 a month unbundled...but stepping up to 150/50 for me runs me $130 a month and 300/75 is something like $200 a month (600/105 is $300 a month. Damn you Verizon!), Realistically all I'd ever really want is a 150/50 and that is a little more for the uplink than the downlink for the occasional times I am uploading a bunch of stuff to dropbox, flickr, that sort of thing where I have a coupld of GBs queued.
