The automatics are no slouch and, unlike the Lowrey, you can, with something like EMC Style Works, convert styles from almost any make to work on the Roland. Easier to navigate and register and that extended lower manual (and the extra half octave at the top) come in very handy at times.
It doesn't have all the bells and whistles of the Lowreys but what it does have is superior voicing, especially on the AT900 and AT900 Platinum models. The Atelier has always been regarded as more of a player's organ. When you want to drive it and play it as a traditional organ, registering your own sounds and playing the old fashioned way (maybe with a bit of rhythm) it gets tricky to get the best from and those wonderful orchestrated styles sometimes don't do that much when you're using only the drums. It was designed primarily for people who play that way. If you use lots of factory set-ups and usually play with automatic styles and bass, the later Lowreys do this very well indeed.
