I soloed Misaki at Uk nationals in November last year, stayed fully KW/versatile (i had a limited collection of malifaux models at the time) and was quite happy with my performance - the only games I lost were against a dreamer player and a tara player, neither of which i'd had much or any practice against before. I've had some time away from the keyword since then and played lots of other stuff from lots of factions. I would definitely solo misaki at a large tournament again.
Her Main KW abilities (assassin and charge through) are extremely simple and universally effective - she's not a master who needs to stay in keyword at all to create synergies and be effective. many models can be flexed in and out depending on your needs (at the moment i'm enjoying taking a kunoichi and kitty dumont who are a great combo in any crew). Also, because her abilities are relatively simple, she isn't at all taxing or tiring to play and I can guarantee that I can play my half of a game with her in 45mins - 1hour and get to turn 5, which i feel is the most important thing in a tournament. also because i can flex alot of the crew around misaki it keeps it interesting - especially for those 6 or 7 game events!
Misaki herself can flex very quickly between scoring/killing. Yes some of the models in the keyword can be a liability (ototo - looking at you) but you just don't need to take them if they don't fit with your plan. The only model I consider an auto-include(*) in Misaki is Jin - he is great with both versions of misaki, generating a pass token, giving you options on scheme removal, enemy model displacement and card draw, none of which you even need to flip a card for. his attacks are fine but not really what you take him for, although if you do get lucky with them he can catch people off guard. (*- the only caveat is sometimes i won't use him against crews that can take alot of anti burial tech for obvious reasons.)
so yea, i love Misaki, i wouldn't say her keyword is trash like alot of people claim, but she definitely benefits from you having a wide collection of minis from Ten thunders to pull from.