I Have an SVP-CL and an SVTIIP pre amp into big iron and they are not the same as an SVT no matter how hard I try.
I've always looked at it that for live purposes, the audience would never know the difference, especially in context of a live band mix. Most wouldn't be able to tell the difference between amp topology, type of pickup, type of bass, scale length, bass construction (or any of the other sacred cows of TB). They don't listen with their eyes as much as some TB'ers do.
Back to the OPs topic - I think almost no one would notice if it was a modeler or not for the bass amp. Even I love the glow of tubes... but hate the weight, the fragile nature of tubes, and the expense of servicing a tube amp.. Comparing a "digital" amp to old school offerings, what they
may notice the bass player can transport his entire rig in one trip. (backpack style bass case, lightweight FRFR cab like a barefaced in one hand, optional pedalboard possibly in the bass case or slung over a shoulder, and maybe carrying some sort of lightweight case for a head or power amp. ) The other thing that
may be noticed is the amp output sounding like the signal sent to FOH if one is super close and there is a good PA in play. The sound guys tend to love my pedalboard setup. One of the "gears" in the 4 onthe floor pedal was actually based off of an SVT. It is a great always-on dirt pedal. I give them a clean mic-level send from my mesa subway DI+ preamp...Sounds exactly how I want to sound. High/low filters on the board to essentially mimic an amp sim and the natural roll off of highs/lows found in most bass amp cabs. For an amp, feed this to a power amp (xls-1502 bridged) sending 1,500w to my two barefaced bb3 cabs. More thunder than an SVT can deliver. Super modular and can run ampless at times.
I think yamaha/ampeg would be more successful putting something out in pedal form or lunch box head (like the mesa subway heads) vs SVT head sized. If going digital/modeling/lightweight, the size of the SVT head isn't a good format for that. Personally, I think my next amp purchase is a Mesa TT-800 for a more basic needs when the board isn't needed.