Family and friends are the absolute WORST at providing an objective critique of your work.
And writing groups are just about as bad. While family and friends refuse to say anything negative about your writing (or even offer meaningful suggestions), writers groups typically consist of newbie authors struggling to compose their very first story, and each wants to make an impact, so you'll end up getting twenty different 'suggestions' for each reading, most of which contradict each other and leave your story floundering with too many off-topic and inconsistent techniques/subplots.
The benefit of an organized class is you're hopefully getting experienced writers, though for most universities, even if the instructor has written a single successful fiction work, chances are, the vast majority of their work lies in writing for Academic publication—which is the polar opposite of engaging fictional writing. :(
That's why many authors plunk down $1,000 a pop to attend 'writing weekends' at select colleges/universities around the country which focus on fiction writing, and where they bring in various recognized literary authorities. Between those voices, the other authors aren't all fresh off the boat, and have useful perspectives as well.
I've never attended, as it's at the other end of the country (the middle-end, that is), but Lake Forest College has a very popular one, as the authors sit around in the grass under the shade of the colleges many trees and get fairly in depth about what works (in fiction) and what doesn't.