I’d go for an A4, having 4 different voices at the same time is very convenient.
A4 needs learning.
I’d say less the options in themselves, that are many and will get you busy for some time, than getting a mental map of the attainable sounds.
It’s not a synth that get you something interesting in the first 20s you own it, most definitely. For someone who wants immediacy, I would not recommend A4.
There are interactions between oscillators waveforms and levels, filter distorsion and resonance, and all the modulations you can set including hidden (second menu’s) ones that need a lot of tweaking before you understand how get control over your sound design. Once you get some interesting timbres, save a Sound patch like you’d plant a flag on uncharted territory, and soon enough you’ll have a shortcuts to reach quickly a sound you have in mind.
It’s only once you’re there that fun starts, and when you exhaust the sequencing possibilities you reach places other synths can’t even dream of. Sound locks, Direct Jump, FX sequencing, slide trigs… A self-sufficient and unconventional synth, really 
5 Likes