Here I go again sharing my GSD website... haha. It will help you start learning about the breed.
German Shepherd Guide - Home
I find the German Shepherd and the Golden Retriever are two very different breeds, especially between show and working/field lines on both sides. I would absolutely feel comfortable saying that German Shepherds are not always an "easy" breed, or for the faint of heart. More often than not they require good leadership skills, dedication to training and exercise routine, etc... you get that with many large breed "working" dogs... but I have seen a lot of GSDs do poorly because owners weren't familiar with "what makes them tick" if that makes sense.
If you get a GSD puppy, or any dog from that matter, from a truly reputable breeder you increase your chances of acquiring a stable puppy that can mature into a wonderful adult. On that same note, the opposite can also occur. Poor judgement on a breeder, or lack of knowledge before selecting a puppy, can result in a problematic dog that could potentially be too much to handle.
There are a thousand and one wonderful things about the German Shepherd dog, but with everything else in life there are always "negatives".. simply be aware of that, and learn as much as you can about both breeds before making a decision - no need to rush, take your time and make a good decision.
What is your expectation of your dog? Strictly a companion? Active or couch potato? Sport or work? Breeders tend to specialize.. "show" animals, "working dogs", "active companions" - though not all specialize. Just more common than not.
Which breeder better suits your lifestyle and needs - entirely up to you to decide after you do extensive research. What KIND of GSD would you like? There are several types, which are listed and described on the website I linked above.
A well bred GSD should be friendly/aloof to strangers, well mannered, intelligent, easy to train and work with - again, all depends on where you go for your puppy.
Good for you for posting here, you are obviously open to learning - it will be lots of fun for you!