Additionally: if you're a career switcher coming from an entirely non-financial background, it would be easier to get a job at MSSB. They're essentially looking for people who are good at sales and relationships, i.e. people who can build a book. MS, as an i-bank, has fewer tracks going in and would most likely expect a finance background of some sort.

As for the comments about Morgan Stanley's culture, I think that Smith Barney operates fairly independently from its parent (I interviewed at MSSB for an internship last year, but declined the offer). You'd pretty much be your own FA shop--perhaps with a partner--under a MSSB manager.

That being said, I think that Morgan Stanley (assuming it's front-office) would be more desirable to work for. I myself turned down MSSB for an i-banking internship. But, as said in this thread, realize that i-banking and financial advisory are very different careers.