Some of you guys just don't have the grips on how to optimally play Thf for tank/solo.
I wouldn't so much call various eva sets "solo" sets per-se. There are various roles to fill on thief other than DD'ing. Some roles involve fighting mobs solo. Some involve tanking for a small (or even semi large) group. Some involve simply kiting.
Here are three of my main sets that I use for these tasks,
Full Evasion
Evasion/DD Hybrid
Evasion/SubtleBlow Hybrid
For career thieves at least, using just one set is a years old philosophy. Generally you stick with a main set that you tank/solo in, and then you deviate during the fight based on what you need.
These are base sets and not perfect for everything as is. Of course there is also the option of evasion daggers, xbow, ungur boomberang. Likewise you can bring along HP gear like gigant mantle and bomb queen ring for some serious fights. Among numerous other tweaks.
For example, if you're soloing even matches, then most likely the 'Evasion/DD Hybrid' build is going to be your best set. For this set, I'd say Denali Bonnet (or possibly that Panther Mask / +1 w/ evasion augments) is probably the best head you can melee in. The reason I don't have it in my inventory anymore is just due to inventory limitations.
In that situation, if you're fighting EM's but somehow your utsusemi timers are bad, you want to switch to full evasion to minimize your risk of damage, until your timers get good, and then swap back to hybrid.
In contrast, you would want to use max evasion on something very tough. Or something you're kiting. When you desperately need as much evasion as possible, and you are at high risk of dying if you're slacking. Two good examples I can think of would be a Brigandish Blade trio I did where I main tanked as Thf and we had a Blu and Rdm. Also I did Ix'Drk duo as Thf + Rdm for awhile, but mostly as Thf + Rdm + Sch trio. Those are two situations you definitely are going to need your evasion. If your timers are really good, or the mob is stuck casting a spell or something, you can swap to your DD set or a hybrid set in the meantime. Or you can switch to the subtle blow / evasion hybrid if you wish.
And in contrast again, a good example of a situation where you'd want to use the 'Subtle Blow / Evasion Hybrid' build as your main build would be, Yovras. They are pretty much pussies, aside from their TP moves. So you want to feed as little TP as possible. Going from no subtle blow gear, to the one I have, is a 10->49% subtle blow increase. This means that you're feeding nearly half the TP you were feeding before; IE the mob will only do TP moves at 1/2 the rate. And that is awesome. Switch to full evasion when timers are low, or Hybrid or full DPS when mp is good and you're confident.
Other Denali Bonnet uses: ~3rd best TA piece in the game after Maat's and Skadi.
Other Optie Hat uses: Not the highest eva, but pretty much the best max eva piece you can bring. Surpassed by Wivre Mask+1 and Emp. Pin, but for many of us, we simply don't have the inventory piece to carry those. Optical Hat adds valuable DPS ability to your max evasion build. Meanwhile, it is a phenomenal ranged accuracy piece. And finally, in situations where your accuracy and haste levels are incredibly low (maybe like fighting a god), and you don't have AnwigSalade(10Acc,3%Haste), you can use Optic instead.
Don't generalize. Denali Bonnet is a phenomenal tanking/solo piece. But so is Optical Hat. If you have the inventory space, use what's best in what situations. If you don't have the inventory space, then you have to personally curtail your inventory according to what you do.