While this is obviously super individual, I find looking at saddles picked by pros to be informative, as they spend way more time on a bike than any of us. Nearly all Fizik-sponsored pros are on some version of the Antares, most Prologo riders are on the Nago or Dimension, most Sella Italia pros are on the Flite or SLR. Of course there are exceptions, but these seem like very tried-and-true shapes that will probably work for most. Caveat being pros tend to ride aggressive positions and have better-than-average flexibility and core strength to support it.
My findings: I like a saddle with a relatively narrow waist (more T shaped than triangular), and I prefer a longer (or at least not a shorty) saddle that allows me to shift forward onto the nose when getting low and aero. I also prefer a somewhat firm saddle; with the exception of gravel/MTB, I generally don’t love 3D printed options as they just feel mushy and cause chafing over long rides.
Given all this the Antares Vento is my fave. I periodically try a few other options (we all seem to believe there’s a magical perfect saddle out there if we could just find it) but nothing ever ticks as many of the boxes as the Antares.
You may not know it quickly, unfortunately. I rode this for almost 2 years. It was firm but not uncomfortable when riding. But, the width was pushing me forward and causing nerve pressure that only manifested much later and was very detrimental. I ended up being off the bike for over 7 months and only now am very slowly getting back.
This is less so a dig on the Power Mirror and more a general commentary on the need for a professional bike fit when choosing saddles. OP wants to do double centuries — imagine the damage that training can do if your seat isn’t perfectly dialed in.
I have SQ Labs. 612 Ergowave. The version that is for positions 2 and 3 out of 5 on their scale. I first tried teh Ergowave R, the one that is for positions 1 and 2, and that was amazing in an aggressive position, like your body just fit into the step it has, but as soon as I tried sitting more upright that step went into me and caused pain. The non-R version is less more smooth in the transition, as a result you don’t quite get the same snug position when super arrow, but it still works and more importantly it doesn’t press into you when sitting more upright. It still has enough of their step functionality that I have no issues with the soft tissue at all. It creates room for it.
For indoor riding I bought one of theirs just from what I learned from the fitter about saddles and what they put in their saddle descriptions, cheap one, and it works very well for the more upright riding you do indoors.