I'd vote for stinkykitty because omg that Gems of Provenance campaign
Visually less impressive than Soul Tear's campaign but holy shit that level design.
And there you have it. Trying to make a 2000 game look like a 2004 game is a noble goal and all, but it is obvious that's not where the meat is.
However, I will even contest the notion that Soul Tear's work is more visually impressive than stinkykitty's. Soul Tear certainly uses high-fidelity assets. (I don't want to single him out, since it is true for a lot of recent mission designers, but he is a convenient example.) The point is, stinkykitty's visuals aren't worse. He has very good visual imagination; knows how to build an effective scene from a few brushes; and knows how to turn the visuals into effective gameplay. Look at his loot placement, or the way he creates navigable routes, and you will see the true power of his design. And it is not like his scenes are all gameplay and no show. Here are just a few that stand out: the underground garden, the multi-level mine track area, the otherworldly architecture in the second mission, the interiors of CPWW, or the Keeper castle in the last mission. These look as good as anything made in Thief. No, they don't use high-res assets, but they don't need to, since their goal is different than the highest graphical fidelity. They are more simple, more essential, and very much in tune with the engine and assets he is using. That's skill.
Now, there are good ways to use high-res assets: Lady Rowena, Eshaktaar and DrK are very good with this kind of thing. And yes, Soul Tear's imagery is also skillful and meticulous. Too bad it is wasted on bad gameplay.
(As an interesting aside, I recall a recent discussion on Darkfate where Soul Tear was
criticising The Black Parade. As his argument went, these are "clone missions" with stock assets and no unique content or novelty, and therefore turning the building process into "ordinary LEGO". If it wasn't obvious already, this cemented the understanding that our ideas about what makes for good fan missions are diametrically opposed.)