It's weird that they would pick and choose which neighbourhoods get a specific speed. I wonder if they only provide the faster speeds to the houses that are closer to the central office. Fibre doesn't have as much attenuation as DSL has but maybe at those speeds and the tech they are using still has some short distance limitations. They typically use multi mode fibre which is for shorter distances. They can put something like 64 customers in one fibre strand as it splits up the colours using a prism at the distribution point where it breaks down to individual drops. At least that's my understanding of how it works. So could be you are further than what the 5 gig service can reach. Either way anything over 1 gig for home internet is kinda nuts considering most network gear is gig anyway, unless you're buying enterprise gear off Ebay.