I always wanted a 303. I found a 404 cheap secondhand and bought it.
I used it some, but my homie has the 303 and I was not satisfied with the sound of the 404 compared to the 303.
I found a 303 seconhand barely used cheap, and sold the 404 for twice the price of the 303.
Now I'm very satisfied with the 303.
The 404 has a harsh sound, I do not like the highs, it sounds like a bad mp3-format with a treble boost.
The feel of the 303's pads are way better.
I don't need 16 voice polyphony for my style, and I don't need more then 16 pads either, so the choice is easy for me.
Another thing that's different is the mic input. I use the jack input because it is mono, I put my SP1200, bassguitar and rhodes in there. The 303 can gain more (even more than I need) then the 404, but the main difference is that the 404 has a stupid filter on that input: if you set the input gain on a low setting, there is a low-pass filter to remove hiss. And that sounded warped dull and useless. I could not pump the volume on max on my SP1200 and then turn the gain down on the 404 until it did not peak, because it was filtering with that bad filter.
The built in mic is bad, and when I compared with my SM57 I realized just how bad it is.
The 303 is also prettier, and I think it will remain more popular then the 404.
