Steel City was selling their laser unit at a big discount at a WW show a few years ago, so I bought one.
I hard-wired the little wall wart power supply inside the pulley/belt housing so I don't need to worry about batteries and I mounted the laser unit to the underside of the headstock instead of the column- that way it stays aligned if I rotate the headstock which I do often to drill in a new area of the table insert.
While it stays aligned and works well, in truth, I rarely use or rely on it other than as a coarse indicator of alignment.
Much more useful mods have been a hard-wired task light, conversion to VFD variable speed control w/digital tach, and a keyless chuck (added after pic was taken).