We've done everything over the years: board in a kennel, or have a dog sitter check in a few times a day (first thing, last thing, at least once in the middle) for social interaction as well as basic "maintenance" of walking/feeding. I think it depends on the dog (size, personality, prior circumstances), and the age, as well as the set-up you have at home. A larger dog that has access to a doggie door and a safe, fenced pen out back may be able to be left for longer periods of time, whereas a small dog needs more visits from a sitter (especially in areas like mine, where there are extensive woods with coyotes and fisher cats that can possibly gain access to the yard.)
A puppy can't be left that long, a rescue dog often can't be boarded at all because of fear of abandonment. We have a rescue dog now (twice abandoned, PTSD) and so she cannot be boarded at all. She goes with us or she goes with our son, who is the only person who can keep her overnight somewhere besides our house where she still feels safe and secure. She's a good traveler and we've had her at hotels before, so it's more about her being with someone she trusts and then she can sleep anywhere.
I'd get referrals from friends, and if you are considering a kennel, go visit and find out about the outdoor play and space to run around, as well as security. We've had several friends who boarded dogs who escaped or were attacked by another dog, and it was awful. We also know many who have found good places to board the dog. If you're considering a place, see if they have doggie day care so you can introduce your dog to the facility a few times before leaving for a while. But be aware that kennels fill up a lot in the summer months, so you may have to search around a lot to find a vacancy.
The nice thing about a pet sitter though is that you have someone watching the house and showing that it is lived in. In this day and age, when everyone is posting vacation pictures on Facebook, we might as well hang a sign on the front door that says, "We're away, come rob us."