With some shows and stages and given the right sound company, ampless simply can save a s**t-ton of work, and sound just great, even with open-air monitors. It all depends, but I've had many successful ampless gigs, even without a fancy pedal board. AND, I still love my bass amp

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First, certainly if some contractor is handling all the PA gear, then it would be a LOT less work for the band. My ampless gig does everything on our own. For that gig, I would just say that it’s about an equivalent hump for equipment, ampless vs amped; but, the ampless setup involves a crap ton more cabling. So, if DIY, I’m not sure I agree that it’s less work. Seems like more to me. Especially at load out, since all the cabling has to be bagged up in an organized way for the next gig.
Second, I would absolutely take an SVT over pretty much any PA, in terms of bass sound, absolutely any time. We have the QSC 153i’s, which are pretty nice; but, I am constantly struggling to keep the bass sound just ok. Both because the 153i may be a great all round speaker, but it’s a marginal bass cab (yes, we also have subs); and because fat fingers tend to inadvertently alter what my channel is doing from time to time. Still, I don’t have to listen to what the audience is hearing; so, the mediocre bass sound doesn’t directly affect my playing concentration.
Third, the IEM’s definitely give the player far superior monitoring for vocal harmonies and tailoring the monitor mix. Almost like being in the studio. As such, the system is certainly better for the music. But, then, I tend to find myself sitting around up on stage intently listening to and interacting with the music, rather than interacting with the audience. So, better for the music, but worse for entertainment. The challenges with the entertainment aspect and bass sound make the whole thing feel way more studio and much less R&R to me. My $0.019, YMMV.