i think the big issue with komplete 12 is that it has a TOn of stuff but sometimes hard to find sounds that are just 'ready' to work with tracks. i think the base version includes a bunch of free extra downloads too as well. Omnisphere is not bad i hear but you have to pretty much pay 500 bucks out of the box whereas nexus you can get the base version and then add packs later on. I even tried otu serum and spire's demos (and serums 3 day trial on splice) and for me i wsnt a fan of the presets the sounds of nexus i think are really nice while there is no demo to download you can check otu the sounds on their main site with a few video previews. spending hours crafting your own sound ? maybe you want omnisphere but if you want a bunch of nice sounds that just works out of the box mostly suited for dance/pop edm etc type music. which just listining to a few of the base nexus pianos seems to do best for a house vibe. I have komplete 12 ultimate and while it has a lot of nice stuff many of the presets arnt just exactly what i want and the pianos are missing the dance type feel. you can always just get the base nexus 3 which should provide more then enough sounds to get you started and an expansion or two then build up the library down the road.

now you can get the full pack but my suggestion is as you get dicounts with more then packs you get. I just wanted to say i got to try out an older version with nexus 2 and i gotta say i love the presets a LOT more then other presets they are far more usable out of the box and for the price id consider the base nexus 3 which is cheaper (just 250 vs like 500 for omnisphere) and you can add like one or two expansion for 15 percent off too so total can be 300 to 350 to start with.

Omnisphere 3