I sort of wonder how I'd like the shoes you've mentioned over the past year, though they are more than I wished to spend. However, there is absolutely no way I'd buy shoes (cycling or not) without trying them on. I tried around a dozen pairs of cycling shoes last year and only one model felt reasonably comfortable, a casual cycling shoe from Shimano. The salesman tried to find me something higher end unsuccessfully.
Some of that is knowing what you have tried on before and reading reviews. If you can get close, most online suppliers have super flexible return an exchange policies on shoes as that's the only way they can sell them.
This set was the third set of shoes I tried this winter to get the right fit. I tried Sidi Narrows too narrow, that was a attempt to get a better fit. Then I tried last years DMT model. I had the 4 hole shoe in 42.5 and I recalled it feeling small at the start of the year. But when the 3 hole 42.5 arrived it was too loose. So back it went. Finally with the last minute switch to a three hole shoe the 42 was a good fit. Definitely a winter project of patience. The return shipping comes out to be about the same as my fuel costs to drive to 4-5 LBS in the 200 mile radius that have good shoe inventory.
I find that sizing for people in the US can be a problem as our sizes don't map 1 to 1 to the EU sizes and each manufacturer is different. I can take any off the shelf size 9.5 in the US and it will mostly fit well. Cycling shoes on the other hand have to fit perfect and you can't compensate with sock thickness. I find for me the size 42,42.5 ,43 all fit depending on the manufacturer. It has been my experience that the size is the number one thing that matters; the upper part of the shoe should must fit and the width of the bottom has to fit. The sole will be totally uncomfortable off the bike, because the stiffer the shoe the worse it feels in the shop and the better it feels on the bike.
In my jaded opinion, the big problem is most people that buy shoes at the LBS want a $50-80 shoe that will last 5 years like sneakers. As a result most of the in store inventory is junk low end and the sizes are spotty; if they have more than 3 styles in your size then you have done really well finding a good store.
Because I'm such an introverted person, I've spoken to numerous LBS owners and they affirm it's their single biggest pain point in the business. This is one reason Sidi is so popular. They have the best subsidy inventory program for shops. Because of that I usually tell people to find a shop with Sidi and go figure out which Genius or Dominator fits their foot. If you find a pair that fits you can do far worst than get those. They will last 8-9 years unless you destroy them in a crash.
Once you have the right fit in a Sidi it's easy to branch out into the online ones; you can usually find a size comparison to Sidi for other brand shoes. OR you can use the Sidi sizing template print on paper. Cut out the shoe size you like; then lay it against the competitors sizing guide and see which size you need.
Phew that was wordy....
Here's a couple of take home points.
1) Sidi, Specialized, Shimano, DMT all make great shoes (there are many others but these are 4 you can count on every year to have new and better stuff and many options)
2) DMT and Specialized are much better dollar values because they don't have the massive inventory programs that Sidi and Shimano do with the stores. You get more shoe for the dollar from DMT and Specialized, but you usually have to get them online. Specialized does inventory some of the mega LBS. If you find a store with Specialized in stock expect them to "hard" sell those to you as the best. This is usually a sign they have A LOT of Specialized stock and feel they have the best chance find one that fits you with the least effort and therefore the best us of staff time.
3) If your shoe has velcro or ratcheting brackets the fit has to be near perfect size wise.
4) If your shoe has boas dials or are lace up (yes high end road shoes with laces are back) then the shoe will shape itself to your foot better. The fit will be more forgiving and feel better. You want the closing system to pull the shoe up and around your foot for the best fit. The bike shoe industry has finally figured out that maybe the old ways were in many ways better; and thus boa and lace-ups are back in full force
If someone asked me to help them with shoes
1) I would send the impatient people to Sidi because you get a good shoe for minimal effort.
2) I would send people that don't take care of their stuff to Sidi because they do last forever
3) Patient people with a budget would be sent to DMT to maximize their dollar in exchange for their time.
4) I must try it on in a store people; Shimano
5) I have tried everything and I don't like it... Specialized because for some reason those people always like specialized.
6) If all that fails the person usually winds up with a sandle or tennis shoe style. Which in most cases because cost was king and that is just fine for the type of riding they do and they really will like the shoe and it will work for them.
Your style of riding really dictates how long you find a shoe comfortable. If you evolve you may need different shoes.
Final thought:
You have boots for working in the yard.
You have dress shoes for work.
You have tennis shoes for around the house
You have sandals for the beach
You have running shoes for walking and running.
Why do you have 1 pair of bike shoes for: Leisure riding, 40k TTing, 80 mile social events, and 100 mile centuries all have different demands.
If I made you walk 10 miles in your sandals you'd get blisters. Keep that in mind when you ask that comfort bike shoe to carrier you on that entire 100 mile social group ride in August.