I, on the other hand, love LEDs.... although the only ones I've tried on a machine so far, I miscalculated the voltage and have burned a large number of the individual LEDs out (oops). While they were working, though, they gave out great light - I used 4x 12v panels of 48 LEDs, glued inside an old filament bulb holder. You couldn't look directly at them whilst they were on, and they lit the work up just fine. Then the magic smoke started to come out...
From a house point of view, I'm completely converted. Most of my bulbs are now LED, I've got 3 traditional filament bulbs left which are getting changed to LEDs as soon as they blow, and a couple of CFLs which I hate.
For machine work, you want to get bright white or daylight white IMHO, warm white is just too yellow. You may also find the reason for your home-made flood being "too dim" is because the LED is in the wrong place for the parabolic reflector; LEDs are, as you know, much lower profile than bulbs, so the reflector needs to be a different shape to pick up all the light. The only way around that would be to make a "bulb" of LEDs (say, 4 or 6, arranged in a ring facing outwards), and mounted in roughly the same place as a bulb's filament would be. The awkwardness of arranging the LEDs like that would probably make it easier and cheaper just to buy a dedicated unit...