Istanbul

[Matt]

Changed some stuff.

Turn four has been roved for a quicker run to six.

Kebab Corner now renamed from Turn 8

Backstretch renamed to 'Straight of Dreams' and curved instead of OMGWTF kinked.

Last chicane complex nixed for two quick sweepers.

[Rockmunky]

Hmm, i like the turns 10-11 section, but i can't say the same about the straight, should have been left with the kink IMO.
nice effort though

[Lustigson]

Not a bad change at all. However, straightening the part between turns 3 and 5, eliminates any overtaking at turn 3. On the other hand, it could provide a Corkscrew-esque drop after turn 3.

I also like your change to turns 10 and 11. Those would be better for F1, although other series (anyone seen MotoGP last weekend?) could still use the existing turns.

The fast right-hand kink I would certainly keep. I love that.

[shambles]

Not bad Matt, although I feel that maybe 3 and could be changed differently. I like the changes to the final turn, but not too keen on the straight of dreams.

I'll come up with my own edit later on me thinks...