Yes, saddles are a subjective and individual thing and yes there’s no alternative to some trial and error testing and yes a good bike shop with test saddles makes the whole process less time- and money-consuming.
But you still have to test. From my experience it helps to narrow the choice of potential saddles down by realising that it’s not only the actual shape which makes a difference but also the padding. Furthermore and maybe most crucial is the type/area of discomfort that one has experienced before.
In my case it’s rather the crotch than the sit bones which ached after a while. Based on that I focused on saddles with firm padding and a pressure relief channel. Padding which is too soft bulges up between your legs. More so when they are old which maybe a reason why saddles become uncomfortable over time. I also found that saddles with a very round surface, i.e. an arch from left to right had a similar effect on me maybe by spreading the sit bones/hip apart (or simply being higher in the middle than on the sides).
In the end I found the perfect saddle for me (SQlab 611). It comes in 3 width, has very firm padding, a flat surface and a “step” in the profile in addition to the channel. The bike shop helped with measuring the right width (without touching 😉 ) and offered to take it back within 14 days of testing. Perfect!
Cheers!
Hendrik
By the way: sitting more upright can also be an (easy and cheap) option to improve on (seemingly) saddle induced ache.