Unfortunately, law school is not for everyone (see the reviews below). However, I would not lay the blame at the feet of what is an excellent casebook. If one is looking for a quick and shallow statement of the blackletter law then I recommend reading Emmanuel's (full disclosure: I was a paid reviewer for Emmanuel's). If you want to understand Constitutional Law without having to read the cases, then I highly recommend American Constitutional Law by Laurence Tribe, which is an excellent book in its own right, and I would strongly recommend it in addition to the Gunther and Sullivan casebook. However, it is necessary in order to gain a full understanding of the law to go through the process of case analysis.
This is especially true in the field of Constitutional Law. While it is perhaps possible for one to become an expert on the topic of Criminal Law or Torts on Emmanuel's alone, it is necessary to read the cases to fully understand Constitutional Law. This is because Constitutional law is composed of primarily three things: first, the text of the Constitution itself; second, historical documentation such as the Federalist Papers (I strongly recommend the Mentor edition); and third, the cases themselves, precedent. This is the stuff that con law is made of, Justice Brennan and the "spirit" of the Constitution notwithstanding.
If you have the capacity and the desire to learn constitutional law, I would strongly recommend purchasing this casebook. Gunther and Sullivan do an excellent job of structuring the cases, and the notes will probe and challenge your understanding of the material, and even provide a synopsis of the "law" in case you failed to read the case as thoroughly as perhaps you should have.