I recently purchased the V collection for VST versions of synths I will most likely never have in my studio. The Matrix 12 sounds just like my old Xpander, and some of the other synths are spot on - but Acid V does not sound anything close to a real 303 (I have 2 real ones, plus an RE, plus 3 TD3s, and was a service tech for Roland in the 90’s). It’s “in the spirit” of a 303, but everything is off from the resonance shape, the 18db/oct filter, the saw doesn’t “pop” when tuned low, and it sounds very artificial and digital when pitched high. The sequencer operation also works nothing like a 303. it should start and stop with the midi clock (or SYNC) just like a real one and every other 303 plugin. You can trigger the pattern when HOLD is on, but then it keeps going after your DAW stops. Yes, you can drag the sequence into your DAW, but half the sound of the 303 is from the quirky sequencer, and the way the notes subtlety "borrow and lend’ time to each other based on slides and accents - that’s what makes a real 303 sound organic (and another thing the Acid plugin misses) , and is why this tiny box is so revered.
There is a huge need for a good 303 plugin, so rebuilding this from scratch would be worth dedicating the resources to. Currently, the best VST is the Roland one, but even that sounds too rigid/digital, and every plugin instance sounds identical where as every real 303 sounds totally unique. Myself, and many other 303 users I know would love to have a faithful VST recreation to use when away from the studio!