I'm a longtime Aperture user who's been trying to slowly ween myself to something else. I've tried Lightroom a few times, previously switching exclusively for several months to force me to get to know it as well as I could; but I found I wasn't enjoying it, the modular system wasn't working well with my workflow, it's auto-adjust which I use on import as a starting point to evaluate my images sucked in comparison to Aperture, meaning more work, and metadata-management was a hassle. So I ended up for a while with both Aperture for all legacy images, and importing new images with it for it's superior metadata management and GPS tagging. Now I've moved heavily over to using Photomechanic for ingesting, file renaming and tagging, including geotagging, before moving to Capture One for editing. Not ideal, but a better alternative for me than using Lightroom, as the workflow is much more comfortable, and I can get the results I am after more easily and quickly than Lightroom.
Over time, I will have to work through the tens of thousands of images in Aperture to clean them up, fix up metadata and write it to the masters, and exporting any pics to jpg so I won't be burned once Aperture stops working. As it is, it still works, but is showing buggy behaviour in El Capitan. There are still looks that I know better how to achieve in Aperture and have presets for; I have yet to rebuild similar presets in C1 or Lightroom for that matter.
So yes, C1 is flawed, as is Lightroom, but C1 fits my needs better once you add Photomechanic into the equation. Mind you, it is hard to get past Photoshop, and that is their ace, since if you are on the Photograhy plan, you have Lightroom, so why pay more for C1? For me personally, it is worth it for the productivity and results. For most casual photographers struggling to justify the Photography subscription, it is too high a price to have both, if they cannot make do with Affinity Photo or the like. I have that as well, but I just know Photoshop too well, and it is still a powerhouse no other software can compete with for certain things. In publishing, there is nothing else. It really depends on your needs, and if you are prepared to get to know Affinity well enough. For the desperate, there is the Gimp, but without a native Mac version, I cannot take it seriously (GTK is seriously poxy and sloooow).
Lightroom and Aperture come from a different direction than Capture One; while the former are for your average photographer as well as professionals using SLRs, with photobooks and social media sharing very much an important part of their mix (eg wedding photographers), Phase One comes from the direction of needing software to support their high-end medium format cameras, as used in high-end fashion shoots and the like, where good tethering support in a Session workflow and specifically good support for their cameras was paramount. Cataloging is a fairly new thing for them, and social media plugins are still alien to them, as is inbuilt photo book support. Or proper metadata management for that matter. Where they are strong is in their RAW image editing and tethering (which Lightroom inexplicably sucks at; even Lightroom people who need to shoot tethered use C1 for that part). With Wifi becoming more prevalent in SLRs and full frame mirrorless, tethering in SLRs might become less of an issue.
As I like to play with new photo tools, I do have Luminar and Photo Raw; I particularly liked playing with Luminar on certain images which got what I was looking for more easily than in C1; it depends on the image and the look you are going for. It will be another tool to try on select images now and then, but without a good DAM component (they say they are working on a browser and batch processing), it is too difficult to work on a photo session, quickly going through picking images and applying edits across multiple images for instance. I am yet to give Photo Raw a good go, but it somehow doesn't feel as comfortable, even though they at least have a browser.