I'm an academic librarian at an institution that also has a library science program, so we get lots of students as grad assistants.
The MLS program is not hard. It may be a lot of work, with assignments and papers, but there is nothing at all intellectually difficult about it.
The pay is generally lousy for requiring a masters degree. If you go to the Occupational Outlook Handbook, you can get an idea of salary and employment expectations. Right now, it's very tough to get an entry level job, but that's true for many fields.
It also depends on where you live. The closer you are to a university with a library program, the harder it is going to be to find a job there.