Just got a set of these Hygia SLP brakes for $200. With stainless braided hoses they are not exactly light. The complete set came in at 768g incl. rotor bolts, mounting bolts and post rear mount adapter for 160mm.
Front brake assembly weighs 246g:
Rear weighs 275g:
Rotors weigh 80g:
So from a weight weenie point of view the only thing decent weight-wise are the rotors.
It is possible to shed almost 120g off the set with the following mods: use shimano post mount adapter (18g), Ti rotor and mounting bolts, A2Z ultralight pads (use XTR version), Jagwire Hyflow hose and aluminum clamp bolts. Total cost for this is less than $100 and brings the weight down to 650g for a total outlay of around $300. That'll get you to within 80g of Formula R1 setup for about half the price.
Performance wise the brakes are powerful with good modulation. Better power and modulation than XTs and Avid Elixer CRs, much more power than older XTRs. I haven't ridden Formula R1 or the newer XTRs so can't give a comparison there.
The levers are the only part of the brake system that seem a bit "cheap". They're made of pressed aluminium. At 8g each they are certainly light, but I've already bent one in crash.
I've just started the process of making some replacement levers in carbon fiber. For the initial set I'm aiming to increase strength without additional weight. So far the results are good. An 8g carbon lever is incredibly strong, so something in the 6g range will probably still be plenty strong and durable. Here's the first lever:
Test mounting:
The lever looks a bit "rough" as it doesn't have the final clearcoat. Once that's on the carbon weave will shine through. I'm in two minds at the moment about whether to clear coat the levers or leave them with the matt industrial look.
More info on making the levers here and more info on the Hygia SLP brakes themselves here.
Front brake assembly weighs 246g:

Rear weighs 275g:

Rotors weigh 80g:

So from a weight weenie point of view the only thing decent weight-wise are the rotors.
It is possible to shed almost 120g off the set with the following mods: use shimano post mount adapter (18g), Ti rotor and mounting bolts, A2Z ultralight pads (use XTR version), Jagwire Hyflow hose and aluminum clamp bolts. Total cost for this is less than $100 and brings the weight down to 650g for a total outlay of around $300. That'll get you to within 80g of Formula R1 setup for about half the price.
Performance wise the brakes are powerful with good modulation. Better power and modulation than XTs and Avid Elixer CRs, much more power than older XTRs. I haven't ridden Formula R1 or the newer XTRs so can't give a comparison there.
The levers are the only part of the brake system that seem a bit "cheap". They're made of pressed aluminium. At 8g each they are certainly light, but I've already bent one in crash.
I've just started the process of making some replacement levers in carbon fiber. For the initial set I'm aiming to increase strength without additional weight. So far the results are good. An 8g carbon lever is incredibly strong, so something in the 6g range will probably still be plenty strong and durable. Here's the first lever:

Test mounting:

The lever looks a bit "rough" as it doesn't have the final clearcoat. Once that's on the carbon weave will shine through. I'm in two minds at the moment about whether to clear coat the levers or leave them with the matt industrial look.
More info on making the levers here and more info on the Hygia SLP brakes themselves here.