Sigh... I guess this is as good a place as any to come clean... I currently own... all three of these shelters (albeit my Duomid is sil, not cuben).
It started with the Trailstar. It has been, and still is, my most often used shelter. I've had it for 4 or 5 years now. I love the wind and rain worthiness of the shelter, the amount of covered space and the simple, yet elegant design. There's something about the look of the shelter that I just really enjoy. I've also found it to be sturdy and dependable and generally have no complaints about its performance. It's an A+ shelter for me and if I had to whittle my kit down to one, it would likely be my final choice.
But I don't have to limit myself to just one, and so at some point along the way, I decided I needed a second shelter... one better suited to winter snow camping applications mainly. Also, one that didn't require me to always carry two trekking poles. So I picked up a used sil Duomid and have used it a handful of times over the last ~2 years. I like it... but I don't love it, like I do the Trailstar. It pitches simply and quickly and it's great for snow. I find it a bit cramped for two; better for just me, or me and the pup. It has a smaller footprint than the Trailstar, which is nice sometimes, although I don't find it as worthy of a shelter in windy conditions or wind blown rain. Air circulation inside the shelter isn't as good either. Still, it's a nice shelter and I plan to keep it and continue using it for certain types of trips.
More recently, I decided we needed a larger family shelter that could handle snow camping or better lend itself to a shared winter shelter for 2 people + 1 or 2 dogs. So I again searched the forums and ended up with a used SL3. I'm actually pretty impressed with this shelter: It's got lots of room, is well made and isn't too much heavier than the sil Duomid. The increased height is nice too. Set up is a little more fiddly with 6 corners to stake out, but nothing outrageous. I cut off the webbing tie out points and added my own linelocks instead that allow me to pitch it tight to the ground or use deadman anchors. The SL3 doesn't get used very often, but it, along with the inner can do double duty as our car camping tent, so I think I'll hang on to it too.
Looks like I'm advocating buying and/or keeping all three. Sorry... Guess I wasn't too much help after all...