After taking a tumble on my bike the other week, I decided to look at the options for upgrading my bike caliper's. I've got a Trek 1.5 H2 2012, bought as Olympic fever was gripping Britain, and ridden exponentially more miles than any other bike I have owned before.
The options on the Trek 1.5 are limited, due to the fact that it requires 'long reach' brake calipers (it leaves plenty of room for mudguards). I ended up settling on the Shimano R650s - not too expensive at ~£28 each, and arrived within a couple of days from the wonderful Wiggle.
Needless to say, they were a cinch to fit, and after making a few minor adjustments to the brake shoes and centering the brakes - have made one massive difference.
With my previous stock brakes, I'd replaced the shoes a few times and maintained the brakes by checking whether they were centered - but the consistency of braking with the new calipers is much more like the brakes on my Dad's Madone 3.1 SRAM setup. I can 'feel' the road a lot better, and even attempted to lock-up on my way into work this morning on the wet road - but was able to feel my way far better than before.
That said, it may all be psychological and the old calipers have just worn from thousands of miles of wear and tear. Do let me know if you've performed a similar upgrade, or have recommendations on what I should upgrade next. By all accounts, it looks like the wheels will be the next upgrade - but that's probably a birthday present to myself in March - once the weather has improved.