omnisphere 2 would utterly completely and utterly sort you out. but that's a significant investment. i have avoided getting this because it;s just soo good...possibly too instantly amazing....and making nice pads is part of the fun for me.
Yeah, Omnisphere is amazing but you're right... it can be limiting if you have a preset surfing habit. Too many sounds, and so many of them are so frigging cool. Of course... that's also awesome if that's what you want. When I get stuck preset surfing, I just start bouncing everything I like and then chop it up, stretch it out, resample and mangle it later.
I found with omnisphere that the ocsillators arent especially great or warm, but the tool lends itself to building complex patches, and thats why it is good and why the presets are good, but you might find with it that unless you are especially good at making patches, nothing you make on it sounds as good as the presets. I prefer a synth where even the init patch sounds phat and go from there, adding complexity with an effects chain if need be
Have you worked with Omnisphere 2 yet? They massively improved the synth oscillator options. Of course, if you just want super fat oscillators, you can use the samples, too... But in Omnisphere 2, you can use synthetic oscillators based on all sorts of analog and digital waveforms (there's a hundred at least), and you can use the synth shape/symmetry/hardsync controls on all of them. Also, Omnisphere 2 lets you use any of these new synth waveshapes as FM and RM sources, *and* you can control the shape/symmetry/hardsync of the FM modulator... Also, their Unison function now has drift...
I agree with you that Omnisphere's blank saw wave is not all that inspiring, but Spectrasonics really did well with Omnisphere 2. I feel like they actually listened to what people wanted, as the mediocre (well, terrible, let's be honest) FM in Omnisphere 1 was totally unsatisfactory and lots of people complained.
And yeah... Omnisphere's presets are great, but it's so worth learning how to program your own sounds on it. It took me a lot longer to learn than say Sylenth, but at this point I wouldn't ever want to be without it. It's so deep and it does virtually everything well, even psytrance bass or massive supersaw sounds.
But for simple and fat... U-He DIVA is my other go-to right now.