La Sportiva Katana Lace vs. Kataki vs. Genius

Long story short, price makes no difference and I am wondering which of these shoes is best for sport climbing, especially for slabbier stuff because I already have a good bouldering/steep shoe (Evolv Shamans). Any input is much appreciated.

The difference in performance is negligible. The difference in fit is not. Try them on.
Mal

if you want it for slab, the Katana lace is the only choice out of those three. The last on a sportiva shoe has a number associated with it, the higher the number, the more asymmetric and down turned the shoe. Genius is PD 85 and designed for competition climbing which is anything but slab. Kataki says "steep edging" in the description, again not slab and has a last of PD75. I have the Otaki which is the velcro version and unless its vertical or steeper, they crush my feet. Katana lace is relatively flat lasted at PD55 and has a small stiffener under the big toe. 

Sam the last numbers of sportiva are deceptive, at least the way we think of them. The kataki actually has a lower volume toe box than the katana lace, kataki does not knuckle up your big toe at all.
From the side brand new the kataki looks more downturned, but it’s really just a long camber from a higher arch.

Their description of the kataki is pretty off on the steep edging too. It’s great on thinner vertical to slab edging, but steep edging they’re no testarossa.

Men’s version with xs edge would be a good candidate for thin edging. The women’s with grip is great if you’re doing more smearing/smedging. I have both for different types of rock.

The katana lace is also a good choice for thin edging. With the full length rubber sole they give a little more support, but they also don’t smear as easily as the men’s kataki.

Fit is also different, kataki is narrower and has a LOT more rand tension on the Achilles.

Genius can work great on smedging type rock like grit and sandstone. Wouldn’t want it on true thin edging