So, what's my own answer to the little puzzle?

Well, before going to the store, I would have prioritized my own needs. That starts with understanding my trips: I backpack in Ohio, Kentucky, and Indiana, which means mild winters with mostly light snow, if any (and I tend to stay home if there is heavy snow or temperatures below 15 degrees.) In summer, temperatures and humidity are often in the mid-80's. Mostly, I do weekend trips, and tend to cancel trips if it calls for steady rain all weekend (still got my "I Can Camp in the Rain" T-shirt.) I don't do high mileage, and while my style is mostly minimalist, I don't equate that with uncomfortable. I'm in my early 60's and not as nimble as I was once, but no particular infirmities. I rarely - lately, never - share a tent with a hiking partner.

So, what am I looking for in a tent? In order, I want:
1. A small footprint, so I can tuck into smaller, more secluded spots.
2. Great ventilation. Since I'm only occasionally in the rain, or in foul winter weather, I often use the tent without the fly. That lets me take advantage of every breeze, and minimizes the tendency of an enclosed tent to overheat.
3. Light weight.
4. A side opening - like I said, I'm not as nimble as I once was, so I want to get in and out easily.
5. Plenty of head and shoulder room
6. Freestanding. Occasionally, I want to pitch it on an open ledge for the view. But mostly, I tend to find that they are somewhat sturdier in a strong wind than a tent that isn't freestanding - and I do sometimes find myself camped in the open in a windy situation.
7. Proven reliability. While I don't distrust new technology, I tend not to be a first adopter.
8. Price. My mortgage and the kids' college are all paid, and I don't smoke, drink, chase women, or own a boat. While I'm a long way from "money is no object," I am able to indulge myself in good gear. All of these tents are within my price range.

So, let's look at each candidate:

Fly Creek: This passes the first three criteria quite well. However, the end opening is problematic: I'd have to do the sit-and-spin routine to get in and out, and it would probably have to be done in and around any gear stored in the tent. Also, given the shape of the tent, there isn't a great deal of head and shoulder room. It's also not freestanding (A buddy and I both went through a 40 mph night recently; he was in a Fly Creek that had a great deal of deflection. Another friend, in a freestanding Copper Spur, had no such issues.) However, the tent seems to be a proven performer - and despite the deflection, my buddy's tent never threatened to collapse. This would be a definite contender.

Copper Spur: Great ventilation, compact footprint. The freestanding feature not only gives it a great deal of stability (see above), and also create a lot of interior volume. It's not particularly light, but not prohibitively heavy ("early 60's" means I remember when 5 pound tents were considered lightweight.) Nothing particularly cutting-edge about it, but a solid performer. Also a definite contender.

Slater: This appears to be a similar tent to the Fly Creek, except that it has a lot less mesh, and more length and volume. The price paid is some extra weight. It looks like it might be a good choice for die-hard winter campers, or for taller folks - but I'm neither. I'd probably pass on this one.

Scout: Definitely light weight, but the limited ventilation and the inability to pitch it without a fly give me concerns about it overheating in hot weather. (I had some experience with a Tarptent doing this in the hot, humid Ohio valley.) The footprint is large, and the large flat ends and walls raise concerns about stability in the wind. Definitely a livable tent, with lots of interior space. All in all, this would be a definite contender if I hiked anywhere but the hot humid eastern US. But, since I don't, I'd probably rule this one out.

Fishhook: This appears to be a near-clone of the Copper Spur, except that it has a "zipperless" door - a new technology that isn't well explained on the website. This would be a contender.

So, now what? I'd ask the staff at the store to set up the Fly Creek, Copper Spur, and Fishhook (side by side, if possible), and I'd start climbing in and out of them. Having actually done this, I chose the Copper Spur because of the side opening; the Fly Creek is just too awkward for me to get in and out of. (If the Fishhook had been available, the decision might have hinged on how "zipperless" works.

I hope this gave you some insight into how to narrow down choices when you're faced with an overwhelming selection of gear. You probably won't be choosing from a single brand, but the general principles apply: define your needs, prioritize them, and then evaluate the finalists based on what you, not someone else, needs.