It's usually extra hostile for things like caching. I've (on multiple occasions) seen one URI endpoint, http posts and method as a separate header. Pretty much as far away from a sane caching best practice as you can go. Also; a lot of these older web services doesn't support deflate, gzip (accept-encoding, vary, ..) so your average responses are 500kb and up. :'(

In a recent project, a client saturated their wire as a result of just this.