The MS-20 can do bass very well, it can't shake the foundation of the house, it's just not used that way too often. The MS-20 will also be well integrated with a full modular if that path is explored down the road. Also 37 keys vs. 25 is a plus to me regardless of key size.

Having had both, the BS is a vanilla ice cream cone, the MS-20 is a hot fudge sundae, and an iconic synthesizer for a reason.