14 RHD, large size, and a continuation of the four-arm theme started by the mezzoloth.
In terms of ability scores, nycaloths are... kind of underwhelming. 20 strength is pretty unimpressive, 25 constitution is nice but hardly great, and the remaining stats (which fall between 10 and 16) are almost an afterthought.
The chassis as a whole, however, offers some neat boons. 90 ft. good fly speed is always useful, DR 10/good will come into play often, and assorted energy resistances have never been bad. SR 24 is a mixed bag, but has its uses, and telepathy is great for obvious reasons.
Interestingly, Improved Grab says that the nycaloth must hit with 'both' claws, despite the creature clearly having four of them. This almost definitely was done so that a weapon-wielding nycaloth could grab if the two claws it was using hit, but sadly causes quite a bit of confusion in almost any other situation. If a nycaloth isn't using weapons, does it just need to hit with any two claws? Can it only grab when attacking with exactly two claws? Or does it have a set of specialized grabbing claws, which are the only ones it can use the ability with?
Anyway, other traits are meh. Rake is good but not great, Liftoff is a fairly typical 'you can lift grabbed creatures under those specifications' trait, Bleeding Wounds adds low amounts of damage-over-time to the claws, and Summon Yugoloth is your typical combination of unreliability and a fair amount of power. Mobility as a bonus feat is unexpected but nice.
The spell-likes are at-will Deeper Darkness, Desecrate, Fear, Invisibility, See Invisibility, Mirror Image and self-only Greater Teleport. Aside from greater teleport, it's all pretty limited low-level stuff, though I guess there is some utility in having your entire party sneak around invisibly.
All in all, I'm not convinced the nycaloth is worth +0 LA. 14 RHD are a lot, and it gets neither the casting, nor the melee prowess, nor the special abilities to make up for it. -0, but feel free to change my mind.
25 outsider RHD and not much extra to show for it. Another one for the -0 pile.