A4 UI is infinitely simpler and much more intuitive, lots of things will feel clunky on OT by comparison, don’t assume limitations you may be resigned to with OT apply to A series, e.g. multi trig actions
the A4 is easiest to master of all by common opinion, for me the OT is still a fascinating temptress, insanely flexible, the A4 scores highest on nuance in sound, it’s very deep and capable of a broad range of sound