Slee was way ahead getting to market so I think most have the Slee. It works fine, but there are some reports of some wires rubbing and potentially getting damaged. I think the wires are connect to a Secondary Air Injection system or something. I just wrapped extra tape on them and the mount edge where they are close. No issues for me on that. I've heard of no issues with the braking system proximity though at all. Slee also offers a mount on the passenger side, but its not specifically made for the compressor and I don't know if it would work with the compressor. You'll have to ask.
I haven't heard much about the SDHQ mount, but I'm sure its fine. Having engaged with both companies, I prefer Slee as they have always been consultative, focused on my needs and never tried to upsell me. They also support the LC community, sponsor events and show up in a meaningful way.