I prefer what we got over this
http://trekcore.com/blog/2018/05/star-trek-discovery-makeup-team-reveals-early-saru-alien-look/
IMO the multi-eyed Saru-concept art looks like it was clearly inspired by eldritch abominations, again showing Bryan Fuller's fable for that stuff (Discovery's registry being inspired by Halloween just being one more example).
Now there is precedent for that on Star Trek: Spock himself(!) was originally designed to look like the devil incarnated.
That being said: I CLEARLY prefer the finished version.
Now here is the thing about final on-screen Saru: I think his alien design looks very generic Star Trek. Like, he could have been a regular one-off Voyager alien, or on Enterprise where they usually had slightly more complicated make-up if they had a singular alien guest appereance.
But it works. Great. Because it allows Doug Jones to act. And his performance is magnificent. Every move of his body, but also, his face. That makes Saru not a great alien design. But a great character. Saru on a still doesn't look too impressive. Seeing Saru in action, he's magnificent!
Easily one of my favourite addition to Trek aliens. More than, say, Denobulans or Talaxians or Bajorans. Just his fear boner...erm threat ganglia is something I wish they would have left out. Maybe they can add more CGI-enhancements in the future. Inflatable blowfish-like gills maybe? Gimme' more Saru anyday!

There is an io9-article with a bit more infos
https://io9.gizmodo.com/feast-your-eyes-on-star-trek-discoverys-saru-original-1826484979
Interesting tidbits:
- They scratched Sarus original design a mere two(!) weeks before filming, and started completely from scratch on him! Well one, good job. But by god must that have been a shitshow behind the scenes!
- That also means, Bryan Fuller had absolutely no input for the final version of Saru, but is fully responsible for the mullrat klingon design, and wanted Saru to have this weird Lovecraftian design. Considering Saru is so far DIS' only addition to the Trek lore I REALLY love, maybe Fuller's original version for the show seems more and more plagued as well - not just from executive meddling, but him seriously being in over his head