-> I took my Lincoln to a local mechanic and told him "This is a
-> heavy car and it HAS to stop when I hit the brakes". My brakes
-> had gone out (to the floor) and I wanted that to NOT happen
-> again. I did not set a price nor ask for 'cheap'. I got the car
-> back and two weeks later driving home the same thing happened
-> _again_. 
   
This is exactly why I did ALL my own brake work even on cars.
I'll bleed them, replace brake lines, rebuild master cylinders,
remove and replace the pistons, seals and brake pads all by 
my lonesome rather than to trust a mechanic.

-> I was furious 
   
Been there, done that.
You should have seen me storm Barney's Yamaha
when the clown left the rear axle pinch bolt out!!!
Voice booming pissed as hell no-one even presumed to give me any shit
but apologized and rapidly replaced the bolt they'd failed to reinstall.
They wanted me OUTTA there FAST.

-> but remained calm when I returned the
-> car and was told he had replaced everything _but_ the rear
-> cylinders which were both leaking fluid (profusely). I

This so very obvious a problem a mere glance should have revealed it.
For the paranoid place a single sheet of newspaper under each brake 
cylinder, start the car and repeatedly hammer the hbrakes a few times,
any leak should be immediately apparent.

-> instructed him to replace the cylinders, bill me for the parts,
-> but no additional labor which he did. So far the brakes have
-> been working but now I'm 'gun-shy' with very little confidence
-> the brakes will continue to work. 

This is why I did all my own work.
Even a few lousy stinkin bubbles in a brake line can cause your
brakes to _go away_ unexpectantly.
Gases being compressable keep the hydraulics from working
and bringing the car ( or motorcycle) to a halt.

The only bad thing that ever happened to me ( minor) from a
home brake repair was I lost the spring from the pliars I
was trying to replace it onto the rear brake shoes on a car where
they retract the brake shoe when the brakes are released.
Shot that spring right into a finger.
My single and worst home vehicle repair incident :-)
Hey when it's your own  ride and it's you and your own's butt on the
line you take care to get it right!
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