This is part of the Roland Fr8x that attracted me. When playing an acoustic accordion you have only one tuning with perhaps a few different reed combinations so you're limited that way while on an electronic instrument you can use different sounds and styles to complement the accordion sounds from the right hand. When playing solo you can emulate a small combo when the situation calls for this.
As for the more pleasing sound, it really boils down to personal taste. You can listen to an expensive and high quality acoustic accordion that is dry tuned and chose a lower quality and cheaper instrument because you find something in the sound that suits you better. These comparisons are very much like those lists of the "best songs ever " because your taste is invariably different than everyone else's. Remember that it's not the price, tuning or size of the instrument, it's how you play it.