As a rabid Broughton fanboi for a few years (and I still am), I swore up and down by my ginormous analog pedalboard. I didn't believe for a second that the Stomp could ever replace my analog setup. But it actually has replaced a great deal of it. It has not replaced many of the Broughtons, mind you, nor can it. But most of the other stuff and a handful of Broughtons have been replaced, which for me is quite a statement.
The Stomp wasn't terribly easy to dial in, and I'm still figuring it out. I have seriously aggravated my tinnitus from sitting and tweaking for hours on end. I have a few great core tones that I've dialed in, but there are so many options at times it is a bit overwhelming. I don't even want to think about all of the time I've spent trying to craft a good crossover distortion or fuzz patch.
I have not purchased any presets, but am still considering it. The factory presets are awful, IMHO. You will learn a great deal from downloading other people's patches and seeing how they create a patch, or watching videos on Youtube of how people create bass patches. The first thing I did was got presets from another Talkbass member to get me started. I didn't use any of his stuff as is, but many of them were a great starting point to help me learn how to dial things in. Dr. Tone also has some great free presets available which will cue you in on how to do some things. A lot of his stuff seems geared towards Billy Sheehan dual-pickup bass tones. I haven't really been able to get much out of it with my own setup. But again, it showed me how presets can be created. I can't really wrap my head around his stuff. A lot of his tone seems to come from compression and EQ's, as opposed to cab sims, for example. Which blows my mind. It's a whole other way of thinking of things. In his demo videos on his site, his stuff sounds awesome. But it does not sound like that with my bass and setup. But again, there were some great starting points in there, and they might work great for you as is. I also got some halfway decent tones from the Custom Tone community on the Line6 website. They have all required tweaking to be usable for me, but there are some great starting points out there.
But most people probably would not do what I have done. My three core tones are a Sunn, Fender, and Ampeg SVT CL. But I'm an Ampeg guy at heart, so each patch has a fairly similarly dialed in Ampeg SVT4-Pro feeding the other amp(s). It's unorthodox, to be sure, but I really love it. the SVT4-Pro is what has taken the place, mostly, of my Broughton SVPre, which was otherwise always on in my analog setup. And even that was feeding another SVT sim with a Mesa 8x10 cab sim at the end.
For the overwhelming majority of the time, most of the tones I've downloaded from others . . . not to mention the factory presets . . . did not sound very good in my setup and required at least some tweaking. But I take what they offer, and incorporate it into the sound I'm looking for, add some cab sims from Shift Line's bass IR pack, and I'm off and running. Now I'm down to just a handful of Broughtons and other things and the Stomp. And my lower back couldn't be happier.
That being said, I'm also not someone who incorporates a ton of different tones in any given set. I find one great core sound and stick with, then add some drive on occasion, maybe some octave, maybe both, maybe some chorus, or all of the above. And the Stomp has plenty of options for those things to keep you happy for a very long time.