I highly recommend thoroughly testing across the mirrors and multithread for more comprehensive conclusion.
Being so heavily invested in only testing to that NY server could give you unrealistic numbers. If they're backed up by more results other servers it's better and even better if that's also backed up by multiple devices/computers on the same network.
Despite the lack of additional data I'd like to see, I think you're right. Especially since you've proven over 400-600 Mbps on occasion.
Even the best bandwidth is not perfect. No such thing, that's why we test. Don't ever forget, the same is true on my end. I'm picky with my providers and I put them under heavy scrutiny but networks can and do become congested on both ends. On my end, I keep only the best performers. Providers that don't make the grade are dropped before the public even knows I was thinking about looking into the company. Only providers who consistently make the grade across key areas are allowed to maintain here. By the way, for anyone who doesn't know, all of TMN's testing servers are consumer grade, 1000 Mbps. The servers are constantly monitored... if one locale requires more bandwidth, more servers are brought online automatically. All with 1000 Mbps connections. You're always going to have resources here. As soon as 10+ Gbps becomes more of a standard, TMN will have it server-side across the network. Some of my servers are already connected well above 1000 Mbps, I just don't advertise it until it's across the entire network. Funny thing is, the people I buy them from don't advertise them that fast either. Probably for the same reason as TMN.
Just because I have mad bandwidth doesn't mean that it can necessarily all be utilized at any time, I probably have a better chance than many average consumers but still, it's not perfect. The day it's prefect is the day I'm out of business. --- and truthfully if it betters our Internet, I'm all for it.
If I had your results I'd see the 400-600+ Mbps and wonder if those moments were my true baseline. If that's true, everything else is subpar. If you hadn't seen those speeds then you might be able to say that maybe your computer or network were incapable. Can't really say that after seeing those numbers... and it's was in a large string of tests. You were pretty damn capable when those tests happened.
At any rate, in my opinion your speed is pretty awesome. You pay $90 for all 3 services? At those speeds! Dude. Lucky. --- although, that doesn't excuse false advertising.
Again, it's best to test across more servers and multithread before drawing a complete conclusion. I'd never blame my ISP until checking those boxes. Keep in mind, TMN is hosted across many networks, it would be extremely odd if they all happened to fail or be degraded simultaneously. If they perform similarly across many servers, it's probably your ISP, network or computer to blame.
It's gets even more complicated when you factor in that some routes to some servers can become congested while others to the same server at the same moment, aren't. What most often matters is who your provider is peering with and who my providers are peering with. If those coincide we're going to have a better chance of making that GREAT connection that we wish would always happen.
Finally saw the video to this song. What the... lol