What kind of user are you? Casual, who doesn't need much Storage, and 64gb is more than plenty? You can be perfectly fine with the 64gb / 6gb Ram version. Enough space for you, and 6gb isn't bad - it's good, and still more than many Flaggships today.
But, 8gb CAN have a slight (!) advantage over 6gb, if you are a really really REALLY hardcore user (for example, when i open Firefox + Chrome after booting up my computer, my 16gb Ram are FULL.), who uses tons of Apps over the day, and someone who really notives whenever an App is loading up, instead of "already there in the Ram"... Then 8gb Ram COULD benefit you, by simply having 2gb additional space to fill up Apps with.
However, don't forget that you don't just get 8gb Ram, you also get 128gb Storage instead 64gb. Storage + Ram together, for "only" 50€ more... I think that's worth it, since with these specs, this Phone can easy peasy last you for 3-4 whole years, and still be very fast then.
But again: It's perfectly legit to save those 50 bucks and go for 64gb/6gb Ram.
I would simply decide with the storage. Are 64gb enough for you, or would you rather have 128gb for the future?
18 hours ago, Carbide X said:
Is it true it is the best phone you can get at this price point (550euro)
No, that's not True. ONE of the best, Yes.
No matter what price, in 95% of all cases there is no "best phone". Every person has different Weightings about what points are more or less important.
If a REALLY good Display,one of the best Cameras AND Wireless Charging is the most important thing for you, you will probably be happier with a Samsung Galaxy S9. it has a better AND sharper Display (YES you can see that if you're sensible enough. 1080p isn't that much, if it's just a Pen-Tile matrix with 2 Subpixels per Pixel, instead of 3), the camera is good, but not under the tops, and it doesn't support Qi charging. S9 will be the better Device here, hands down.
On the other hand, if you're a person, who wants a clean OS without many "gimmicks/bloat", maybe some features under the hood, extremely high performance in day2day usage, and easy to Root + Custom Roms with a good XDA dev support... Oneplus 6 will probably be the better device.
Those were just 2 examples how weightings could differ from person to person. For person A, Galaxy S9 is the better one. For Person B it's the Oneplus 6.
Who is now right, and who wrong? Both are right - for their OWN case.
Find out what points are important for YOU, and then you can decide.
However, if you don't need the sharpest Display etc, you won't regret going for the Oneplus 6.
Especially now, that Oneplus promised to deliver 2 years Feature updates (android versions), and 3 years Security patches - counting from day of release.