Hell if I know - who has time for using
this thing when I spend every available hour writing a frickin' patch editor for it??
In seriousness, I'm not a very good musician and I've hardly put it through its paces compared to a lot of more qualified people. But, my quick opinion (and possibly the general consensus) is that the modulation effects are great, the amp/distortion sims are weak, and the reverbs are so-so.
My only Ensoniq experience is with the limited effects in my SQ-1, which I believe
are the same lineage as the DP/4 but a tiny subset, and my opinion is that the reverbs and chorus/flanger are really nice and lush, a bit reserved, quite professional sounding. I get the feeling Ensoniq effects are more about quality, while the VF-1 embodies the general vibe about BOSS: great <---> crappy and everything in between. The VF-1 has a rawer, less organic sound to it, but way more potential for pushing things into crazy territory. And the quality of some of the effects just might surprise you!
Again, I don't think anyone's using the VF-1 as a "high quality studio effects unit", especially with all the DSP evolution that's happened in the last decade (hardware, plug-ins), and I think there's some crazy good stuff out there for all kinds of budgets. But, as a tool in a musician's rig, for bass/guitar/keys/whatever, I think it packs a ton of wallop in a little unit that you can get for ~$175. I'll shut up now.
Oh, and thanks for the compliment! Making it look the way it does has been one of my favorite things about making the editor.