Borderline frame sizing - choose the bigger one or the smaller one?

[Venod]

Just bought a 57 Kinesis over 54. It took a while to decide.

How tall are you etc?

Chose 57 over 54 because can get the reach the same on both with just a 1cm different stem and the saddle bar drop i think will be better on 57. Only real diff seemed to be amount of seat post showing.

I am 5' 10" 32 inside leg in trousers, I have 100mm stems on both bikes. pretty much exactly the same set up,

Ones a Pro 6

The other a Granfondo

 

[JasonHolder]

Smaller one every time. 5ft 9 on a 51cm. Perfect