I think a bad interview process is a warning sign, but not a good enough reason to completely disregard the company. Consider who your immediate supervisor would be and how he or she compares to the interview process. I would rather have a great boss working at a company with a poor HR/interview process than a bad boss. A great HR department will not make up for a bad boss. If they were that great, they would have already gotten rid of him.

They offer good pay, benefits and office space, so someone is doing something right. Maybe they're not so good at the technical part. That's why they're looking to hire you.