Hello everyone!

I never had a BMW car so please help a BMW noob.

I am planning on buying an F12 BMW6 model here in Europe (from Germany's market) and I am having doubts whether to buy 640 or 650 model.

Both models have very similar prices. First I was looking at 2012 650 models but then I read on the internet that the N63B44O0 engine has mayor issues with valve seals which give out and the engine burns oil), I also saw several videos on YT about that problem.

Now, I read that in 2013 BMW revised the engine which was then called N63B44O1 and I am here asking the community( especially the owners of 650 with this engine) does it have the same reliability issues or not?

I fancy the idea of having a V8 engine but if it is unreliable I would rather buy inline-6 N55B30 engine for which I read it is quite reliable.

So basically my question now is it better to buy 2013 640i with N55B30 or 2013 650 with N63B44O1?

And also, where the model of the engine can be found so i can ask the dealers to send picture before purchase?

Thanks in advance for honest help/answers.