I've never used/heard a NEO, but have installed and played a variety of pins with the PinSound 1 and PinSound Plus boards. Either will work with OEM or upgraded speakers. If mono pin you must rewire for Neo but if you buy + and don't rewire you're not doing yourself any favors, as I highly suggest buying the PinSound stereo wiring harness. I think the main thing is that with NEO and sound quality with stock speakers, is you don't have the 4 band equalizer adjustments (Sub Bass, Bass, Medium, Treble). Also, the sub booster control on NEO is a 3 position switch instead of a dial.

I think that NEO would be a good option for a budget user and upgraded speakers, but personally I would opt for the PinSound Plus to have better control over the sound.

Here is the comparison matrix if you are not already aware: https://www.pinsound.org/pinball-sound-boards-neo-plus