A few years ago I owned a Dangerous D-Box that had 8 channels of summing alongside monitor control. I liked it, because it gave me that little bit of extra depth and detail in my mixes that you get with analogue summing, but I ended up selling it when I stopped doing audio production full time. After a few years away from mixing I have recently got back into it and was looking around for a budget summing mixer. I don't have the budget for expensive studio gear any more, but I kept all my 'good stuff', like monitors and interface from before. I saw Paul's Vintage Maker site and read a bunch on passive summing and decided to get a LittleOne 16. The process of ordering was excellent, Paul provided all the information I needed in a direct, no nonsense way, and he built the unit and sent it within 2 weeks.
Once I plugged it in to my system I was immediately happy. The mix I had been working on now had that little bit of extra 'roundness' and 'depth' that I was missing, and I could hear more detail in things like reverb tails that helped me finalize the mix.
The best thing about the LittleOne 16 is that I can run the output through different preamps to get different colouration. With the Dangerous D-Box I always thought it was a bit too 'silky' and 'slick' for my taste. I prefer my music and production to be more low-fi or 70's sounding, so it's fantastic to choose what you run your summed mix through to achieve the coloration you want. I'm not dissing Dangerous at all, their products are great quality and the D-Box monitoring was first class, its just the summing output wasn't completely to my taste.
If you have a good quality stereo preamp to run this unit through to make up the gain, then get a Little One. You'll be happy with the result.
My current production tools are; Pro Tools, UA Apollo Interface, Focal Speakers and some good quality preamps. I definitely hear a (good) difference