As others have said, cr/t is meaningless. Cr/hr is what you try to keep high.
Most people posting 8+ M/hr are talking about routes that last 30 min to an hour, which to me, is not a good trade route. The only time that's good is when you have a bunch of them (routes) all close to each other and you can change routes quickly as they dry up.
I have traveled around quite a bit in PP space and non PP space, and the most I've seen SUSTAINABLE is about 7M/hr (in a 436t Conda), including smuggling. Some may make a little more if they're running a stripped out (no shields, low spec/weight modules) Conda or T9, but not much more.
IMO, when you get to Python/Conda/T9 time, you should shoot for 7-8 M/hr, and don't bother wasting time looking for unicorn routes.
1- agree CR/hr is what matters - so what does it matter if someone at 8M/hr has route that lasts 30 min to an hour, long as it is accurate 8M/hour?
I prefer the comfort of shorter more frequent routes to get to same CR/hr, but whether short or long, if the CR/hr is the same - why do you first say (correctly) that CR/hr is what matters, but then say immediately after that people who post 8M/hr with 30-60min routes is not a good trade route? It's the -same- CR/hr, no?
2- Been sustaining the same trade route since starting game bit over 3 weeks ago - so not sure if 3 weeks count as sustained to you but for me right now it does - and appears sustainable indefinitely from my observations thus far
a) 9.16M CR/hour with Anaconda 448 ton cargo spec, 12 min round trip route
b) 8.6M CR/hour with slower Type 9, 496 ton cargo spec, 15 min round trip route (ran majority of my trade time in this type 9)
c) 2M CR/hour on same route when first starting out with Asp, upgraded to type 7 3.57M/hour, then type 9 upgrade as above
I have found a couple lower ~4k CR/ton profit routes that translates into about 85% of this best route, so I know more are out there, but once I found this one, no point moving on so admittedly haven't really looked much in past ~2 weeks.
I agree that for Anaconda/T9 - 7-8M/hr is good reference point to shoot for. For Python I think that is bit high - it's more reasonable to shoot for about 5.5 - 6M
I lost my notes from brief period I had trade Python which is why I did not include states above with other ships on same route I've been milking, but best I recall it was ~6M - but since this is best route I've ever seen, 5.5M seems more reasonable to tell people to shoot for with trade Python.
Only advice I'd give re: wasting time or not is if you are 100% trader then it would be wasting time. I consider myself a primary trader but I couldn't play Elite so much unless I broke up trade sessions with other stuff. So I generally play 50% session trade, and then 50% missions, explore, etc.
I would tell similar minded people to just use your non-trade session time to keep eyes open and find those golden routes - that's how I found mine, just doing missions and noticing what was sold and for how much, buy just 1 test item and carry it to whatever station your mission sends you to, so no thinking or lot of effort involved - if you take a loss, its just 1 item. But you find some good routes that way too.
you can milk your golden route AND look for more unicorns is my message. if you play more than 100% trade of course.