I've carried a Basic42 for about a year. LOVE the constant output and the tint. I mostly use the primary and secondary settings as I usually have alarger light for when I need more serious output.
I saw the initial thread of Milky doing the mod and I was somewhat concerned about the tint as I really liked the tint of my stock 42GT. He put a USW0H in mine and I couldn't possibly be happier. I'd guess the output of the max level went up 50% or more, but more importantly to me, the secondary setting after the mod is almost as bright as the primary setting before the mod so instead of 6-8 hours of runtime at 10 lumens, now I have considerably more at maybe 8 lumens.
Plus, on primary and max, it has obviously more throw, yet at the same time, the hotspot is larger in diameter. You can either use the stock HDS reflector and use an SSC LED, or use a Q3 reflector and a Cree LED. I went with the SSC because I wanted to keep as much throw as possible and, again, I couldn't possibly be happier with the results.
Honestly, in my opinion, there is basically no direct competition with the HDS lights. The McGizmo lights are outstanding, but don't have as many levels of output. Being a single stage light, I wouldn't want to get any more brightness at the cost of less runtime on the max level either.
There are only ways I'd want to see the HDS improved... and one defies physics. I'd like it if the max, primary and secondary stayed as they are, but there was a switchable diffusion. Obviously, not possible. The other thing is I wish that an 18650 body was available for less than I paid for the entire light.