So, I know that the E2E line of SF is a bit dated, I'm on my second bulb, and given the cost, I'm thinking on an LED conversion head. The SF conversion is cost prohibitive, so my first choice is the Malkoff Devices, made in America and seem to get good reviews, second choice is Lumen Factory, overseas, however they seem popular?

Not really sure which conversion head to get, so if you have past experience, pls chime in. Opinions and personal experience reviews are welcomed. Thanks in advance.