I guess everything about Omnisphere was already said (more or less), but here's some of my thoughts anyway. I have used Omnisphere since before it even existed, kind of
It started its life as Atmosphere in the early 2000's. This was more like a "pure" rompler, and probably a big reason why some people still think of Omnisphere as "just a rompler". Atmosphere quickly became one of my most used instruments, and the same has continued with Omnisphere up to this day. So everything I say here is not biased, it's SUPER biased!
Random thoughts, in no particular order:
- One of my favourite hobbies is to sit down at the DAW, open Omnisphere, start with a clean patch and empty mind, then start randomly browsing the endless soundsource library, until I find something cool. Then just start messing with it, maybe turn on granularity, some effects, etc. After a moment, I might very well have a new patch that I couldn't even imagine a moment ago. Yeah, you can do the same with many synths, but Omnisphere's relative simplicity combined with the HUGE soundsource library just does it for me.
- One of the best tools in Omnisphere is Sound Match, which lists patches similar to the one you currently have loaded, sorted by descending similarity. It's an absolute life safer with a huge library like this (and it also works with 3rd party sounds, assuming they are properly tagged), and I use it all the time to find the sounds I need.
- As others here said, it's super cool that you can use Trilian and Keyscape through the Omnisphere GUI & engine. For example, I have used the Trilian electric bass sources with the granular engine to create some really cool hybrid plucked / bell-like instruments.
- Omnishere was never meant to be a sampler or a competitor to something like Kontakt. They did add user sample import at some point (due to popular demand, I guess), but it's very limited, just a single sample (per layer) and that's it. The playback engine does support zones and round robins and whatnot, but there's no editor for that. Maybe they will make it more extensive, but meanwhile, it's still perfectly usable for toying with your samples and creating something strange/wild/unique (instead of building a multi-sampled acoustic guitar, for example... but there's Kontakt for that).
- I guess some aspects of the engine / GUI / design feel slightly dated... no audio rate modulation, for example. But then, Omnisphere is also pretty CPU friendly, I think. If I want a cutting-edge "analog" sound with all the latest DSP developments, I usually turn to something else. But whenever I need a huge pad for example, Omnisphere is always where I start.
- There are a lot of fantastic 3rd party libraries for Omnisphere. The factory library is already huge, but I'd still recommend checking out sounds from The Unfinished, Man Makes Noise, Hollo, Soundescape, etc, just to name a few. Great stuff.
- I think one reason why there is no "lite" version is that it would make things complicated with 3rd party libraries. As many pathces rely on the factory sample content, there would have to be separate libraries and patches for lite and full Omnisphere.
There. After using Omnisphere (or its predecessor) for almost 20 years on several albums, game soundtracks and other projects, I'm the first to admit that I can't say anything objective about it. But if it still remains the plugin that I often reach for when I just need "a sound", there must be something right about it!