NAS storage… Do you use them?

My manager has started looking into a NAS storage device. We have no experience with them. Currently we’re using tapes for backup and are looking to get away from them if we can.

We a small to medium size manufacturing company. About 150 emlpoyees and are building a new store in a neighboring town this spring with about 75 to 100 new people.

Do you use a NAS? What are some advantages and disadvantages or them?
Are they worth our time and effort to use for backups? What about storing weekly, monthly backups will they do that?

Thanks