Wonderful layout, this track is extremely enjoyable to drive, some of the fast chicanes are a real pleasure as the camber helps you build speed. I enjoy turn 1, it's quite different from the rest of the track and the elevation changes give the track a unique feel.
This track runs perfectly well on my computer - I get over 200fps everywhere so for me there is lots of headroom for the things I will outline later!
The main reason that this is not 5 but 4 stars is because the track lacks unique scenery. It took me a few more laps than it usually takes for me to learn this circuit when compared to others, and that is due to the repetitive scenery of trees and concrete walls.
Take Suzuka for example, it has a Ferris Wheel, Monaco has the Casinos, Silverstone has the pit building.
This track is great but it lacks that one unique feature, the one part of the track that makes a great track a fantastic one. I'm not saying add Eau Rouge or Tabac or Copse but I think you could add something that sets it apart.
I would also as a matter of necessity implement some grid markings and an overhead start light gantry. I would also like to see some pit paraphernalia and generally more detail.
As for the pits, make sure to add a speed limit - the norm is about 80kph.
This detail could be in the form of extra sponsors, grandstands, tyre marks in traction and braking zones - maybe even some resurfaced parts of the track especially in the most cambered zones - look at the Karussell at the Nurburgring.
Another thing that I would look to improve is the replay camera's, it doesn't personally effect me, but may encourage people to make YT videos on your track!
I feel like there is a lot of criticism in this review - but honestly I love the track - I probably wouldn't have written such a lengthy review if I didn't care! It's a great start, well done and stick at it!
Good luck!
I too have noticed the frame drops, so my current build is looking to address them, have done some work on optimising the ground mesh more, and have also culled a heap of trees, as well as removed a heap 'doubles' as the initial method I used for placement was quite inefficient. So hopefully will have some gains there...