This is quite possibly one of the dullest questions to grace this forum today, so sorry about that.

Anyway, new wheels and moving from centre lock to 6 bolt. Currently running 180f and 160r which is mostly fine but back a bit under braked.

I Was thinking of going 180\180, however is there any downsides going up to 200 on the fromt. Cost is largely the same for either.

It would appear to be more power & potentially more modulation for no discernable extra cost.

General trail centre riding, but am planning on the Pyrenees in the summer.

You would also possibly need new adaptors for the callipers.

The other thing to consider is that your forks may not be rated for a 200mm rotor.

It is also worth noting that the rear will always have far less traction when braking as your weight is being pushed towards the front of the bike.

My main reason for running larger rotors would be brake fade, but that isn’t a problem I have ever had in the UK.