Do you ever get clients/customers who just want the companionship and don't expect any sex?

Yes, quite frequently, although I don't know how universal that is. A lot of my client base consists of men (and yes, they're always men) who like me because I'm educated and a good conversationalist.

As for whether they're more or less interesting: it depends on the guy. Some of them are soooooo boring (no, dude, I don't want to hear about your money troubles, especially when you're spending $Texas on seeing me). Some are pleasant to talk to, although not generally to the point where I could see myself hanging out with them off-duty. I do prefer the clients who talk to me and treat me like a person (if a rather attractive person that they probably intend to have sex with) than the ones who are just looking for a hole. The latter should probably just invest in a realdoll.