There is nothing wrong with my brakes! The braking is by far the most powerful I have ever used, even on 160mm. More powerful than my Record dual pivots, more powerful than my V-brakes. Really, really good. I never had a problem with the braking, just wondering "why not more?"

I think this comes down to a definition of "lock up" the front wheel. Perhaps it is a USA meaning, but it seems most people here take that as meaning lifting the rear wheel. In that case, yes, I can do that. Easily. In fact, coming down my ramp to the parking at work I do that every day, just for kicks. Then again on the way back up. Well, this seems like a pretty strange definition to me - how can something that is "locked up" still be turning?? But, yeah, I do this. In the few emergency stops I've ever made, I lift the rear an inch or so then ease off. When I said the front wouldn't lock up, I meant skid (eg, stop turning) on good roads, I still don't think that is possible with good slick tyres.

With 203mm now, once bedded in, braking that was easy is now even eaiser. The bike feels nicer to ride. Stopping feels REALLY good. I can stop very slightly faster and the modulation is great. I love it.

As for damage to the fork. Well, for the same pull at the lever, yes. But I'm pretty sure me+bike (less than 70kg) stopping a little faster would put less strain on than some big fat guy stopping on 160mm rotors. You might argue all the more reason to keep the rotors small if I'm fit and light, but, well, WHY NOT? It feels great! The braking torque is only 25% more for a given pressure at the lever - this is less difference than the leverage difference between riding in the drops or on the hoods.

Plus, rigid forks have a lot less to strain than suspension forks. There's a hard limit to how fast you can stop no matter what kind of brakes you have (I've read in the region of 0.35ms^-2) just because of the dynamics of a two wheeled vehicle.

I wouldn't recommend it for everyone. But for me it is just a little more fun, just a little safer and just a little easier to ride now. If you are strong in the upper body to brace yourself and think you can get used to the more powerful braking (and, let's face it, we all did going from cantis to v-brakes to discs) then I'd say big rotors are worth considering.

Yes, completely unnecessary but for £15 could be the most cost effective upgrade I ever did. Given I'd have paid about the same for another 160mm rotor, well worth it.