The problem with this kind of binary question (full vs fin) is that this is only one of many design details which contribute to a sailboat's overall sailing & cruising characteristics. The right answer will be as much dependent on the type of sailing you are planning (including crew considerations), as any single vessel characteristic. And no matter what, a poorly designed sailboat, no matter what the keel, will be a poor sailing vessel (although it might be a great live aboard).
I have owned both modified-fin (3/4 with skeg-hung rudder) and full keel cruising boats. I have also cruised fin keel, spade rudder cruisers. For my style of cruising I have currently settled on a full-keel traditional boat (Rafiki-37). The tracking ability makes it more forgiving, and I appreciate the ability to take a grounding with slightly greater comfort. But the negatives are significant: tight manoeuvring is very difficult and reversing is a crap shoot (I never know where I'm going to go).
Every boat is a compromise. The real trick is to understand what kind of sailor you are, and where/how you plan to sail. From there, you can start to make some rational decisions about keel and hull design, rig, size, material, equipment, aesthetics, and a hundred other factors.