So there's a few factors as far as I'm concerned.
Hardware
Ergonomics: it looks like the Rift CV has the better ergonomics.
Lenses: I've read that Rift CV is a little better.
Screens: I've actually seen most people saying these are about equal.
Motion controllers: Vive is launch with these on day 1, Rift only gets this at the end of the year. But other than that it's a matter of having a wand (Vive) versus a grip (Touch). Personally, even for seated games I'm going to want motion tracked controllers (Windlands is a good example of a game I'd want to sit or stand in, but still have independent hand-tracking).
Room-scale: My living room is the right size for it, so I'd prefer to have the capability for it when I want to use that. Now, Oculus might be capable of this when Touch launches, but their focus on dual-front cameras to prevent occlusion also has developers such as Owlchemy Labs (Job Simulator) saying that the games work, but need to be more 180 degree focused than 360. Logistically though, (biggest advantage here) wiring two 'dumb' laser emitters in the corners that only require power is far easier than connecting two cameras back to the PC. Someone mentioned cable management as a problem, but everything I've read says that HTC/Valve consciously stopped handling the cables for users specifically to see if it's an issue, and most people forget it's there.
Software
SteamVR vs Oculus Home: I prefer all my games to be in Steam where possible anyway, so I don't like the idea of needing another 'pool' for VR games.
Exclusivity: Oculus is funding developers directly, and those that they fund will release for Oculus-only (Oculus Story Studios, EVE: Valkyrie, Lucky's Tale, Rock Band VR). SteamVR is open and in theory (but maybe not initially at launch) should support the Rift (which makes sense because Valve only will make money off the software). It works with the DK2, but might take some time to get Rift CV support.
Non-gaming software: Oculus definitely right now has more of this available, with (based on the GearVR) Oculus Social, Video, 360 Photos, etc. I wonder if SteamVR's focus might be too much towards games (which is ironic, because I think Vive's touchpads over Touch's joysticks are probably more intuitive for non-gamers).
Chaperone and other software perks: Honestly, I love some of the stuff Valve is doing with Chaperone (these sorts of safety measures which Oculus isn't publicly talking about working on seem hugely important for room-scale, and maybe by the time Touch ships, Oculus will have something similar). But I really love this "Vive Phone Services" concept as well. The idea being that when I'm using a VR headset and have headphones on, I feel completely cut off from the world. I actually have a GearVR (but my phone service is not on that phone) now as well as a Rift DK2 that I took off somebody's hands a while ago, and this feeling of being unavailable does limit my time using VR quite a bit. The Vive connecting to my phone via Bluetooth and providing calls and texts should theoretically alleviate that problem, and it's something I never would have thought about but makes perfect sense.
Price
I expect Rift + Touch to be about the same price as Vive, and so this isn't really a factor to me.
So yeah, in my case, I've made the decision for Vive. I could definitely see why someone would disagree though.