I started playing CoH in issue 3. I knew nothing, had no real life friends in game - didn't even know there were forums for the first year I played. My ineffectual play certainly permeated through to my characters.
Eventually, when I finally learned of the forums, I came across a fire tanker build, designed by Mephe (Mephisto may have been the full name. It's been a very long time. A dozen years or so.)
Mephe broke down each power, why to get it, how to slot it. An guide for the ignoramus that was me. Sadly, I'd already had my tank started - Fire/Stone. I didn't enjoy the lower level game. So weak, always needing blues, because before ED, we didn't slot for endurance. 2 accuracies, 4 damages. Or 1 Acc, 3 damage, 2 recharge. There were no IO's then.
But, I digress. The short answer is I loved the fire tanks until they nerfed Burn. I went IOs because they could make my character stronger, more efficient. I had the resources from farming for purples and those Super Packs which gave all sorts of things that made the market pretty easy to play.
As for incarnate slots, usually, I went for whichever one gave the endurance boost. As for Judgment, I went for the one that brought all the electricity out of the sky just for the effects. Pretty awesome.
I used to think I was a min/maxer - and I tried to be, but I just wasn't that good at the math, and it was a lot of work to do that. I would invariably come across some great builds on the forums, load them into Mids' and then tweak them to my style of play.
The poll - showing Will Power as #1? I don't think that's a fair representation. The folks that stopped playing when ED came out, and also when ..I can't remember! The other game Cryptic came out with after Paragon Studios got CoH from them. The other comic MMO - a lot of those guys played the invuln/SS tank build. I mean A LOT of them. Everyone had one. I even made an invuln/stone. They all wanted "Superman".
I think if everyone who'd ever played were to participate in that poll, the invuln/SS tank would probably have the lion's share of the votes. Once brutes came out, the farmers stopped playing the fire/fire tank. But, there sure were a ton of them, too. Those two and the stone tank were probably the most popular.