Like most people here, my builds are dependent on the hosts that other people can machine and driver boards that other people can produce. Between 2007-2011, I was building a lot. We had CPF members such as LEDzeppelin who could machine LED heatsinks for Fivemega and Surefire M6 hosts for builds that were FAR beyond any LED light that you could purchase, even from the chinese manufacturers. IIRC, the Sandwich Shoppe were the first to offer quad Cree XR-E heatsinks for Maglite mods made by Modamag. These were my first successful builds. Cmacclel made some incredible Maglite mods back in the day, but had to stop after Maglite threatened to sue him.
These days, there is not a lot of point in building for most people, when you can buy incredibly powerful LED lights off the shelf for a third of the price. I would still consider building today, but only if I can find the right hosts.