Consider your needs. Do you prefer a studio experience at a retail location? Would you mind partially working with studio staff instead of your photographer from start to finish? What are your expectations and what feels important to you? Studios can usually offer 9-5 opening hours, which makes it easy for your to pop in at your convenience, whereas a photographer without a studio space arranges to meet you at a location or in your home.
Studio photographers often use off-camera lighting and shoot indoors with props and sets. On location photographers will most often use the available natural light and help you decide what kind of environment to shoot in. These are the norms, but I encourage you to call to hear all the options either one offers.
Many photographers are a one person operation who work behind the scenes at home and will deliver products to you. When you call, you know your photographer will be the one answering the phone and that might be something you prefer. Both studio and in-home pros come with different benefits and perks. It's only a matter of deciding what feels like a good fit for you.