Very addictive and more than just hack and slash.
Think planning, strategy, customization and fast paced combat and you'll be in the correct frame of mind. A very mature player base, so ask someone to help when you first get in and you'll be overwhelmed with the support offered.
Play for a month or two, then come back here and tell people what you think. You won't be disappointed. Then when you think you know what you're doing start researching all the options available to you in creating a character that specializes in exactly what you want.
Play that toon through and have a great time. Then, just when you are an expert, try a totally different class and get blown away at the role reversals and experience the excitement again!