Overall, poorI've used them to manage domain names and a few of my client websites. Some clients just are used to GoDaddy so I don't argue if that is what they want. But I cannot stand their internal system.
First of all, there are ads every click of the way to get setup. Be careful or you might find yourself setup for 5 years instead of 1. It hasn't happened to me (it has with domain names), but I know it is quite common. But they still don't change it because some people don't care to argue. GoDaddy makes a lot of money from that technique alone.
Many scripts do not work out of the box. I've used their Linux and Windows servers, but mainly their Linux. They have very strict rules on the php mail() function, phpinfo(), I've had trouble with ReCaptha 2, and a few others that escape me right now. It is, in my opinion, unnecessary.
As for tech support, sometimes you get people who know what they are talking about, others haven't a clue. But the one common trait I've seen is stubbornness and overall a sense of irritation (or maybe I put that on them, who knows ). I even had one sales force deals and domain name renewals on me to the point where I reported him. Yes I could've hung up, but he was doing actual technical support for me and I needed that done first and foremost.