I tried rebuilding my stock master on my '00 twice, once with an aftermarket rebuild kit...which did nothing, then rebuilt it again with OEM parts to no prevail. So I tried another Kawie master from my '04 I had in my tool box, it was better, but not great...I ended up wasting $90 bucks.
I even tried using a longer adjuster bolt on the Kawie master, but I just couldn't get the feel at the lever as strong and precise as I wanted.
Once I put the CRF master on, it was totally different, super touchy and responsive....then adding the s.s. line shortly there after, was the icing on the cake.
Another thing we all need to consider, is that we all have different preferences and riding styles, and not everyone prefers them as strong/responsive as the next guy.
With that being said...
I like my front brakes to be as strong and responsive as I can get without having to spend the money for an oversized rotor...I adjust mine at the lever so if I spin the front wheel whilst off the ground, you can "just" hear the pads touching the rotor....I run a longer adjuster bolt, and I even swap out the lock nut on the lever adjuster for one half or even less the thickness, so the adjuster can go in even further.
The way mine are now, set up with the CRF master, if I pull in much more than 1/2" on the lever, I'm lifting the rear wheel...if I let any of my buddies ride it, I have to warn them how touchy the front brakes are....unfortunately there has been injuries from not saying anything.
And just like carbs, no two masters are exactly the same...the slightest discrepancies will give different results.