I've always thought that CFHTTP had alot of overhead. a year or two ago we were looking at switching to php (have since dropped that in favor of .NET), and had a php programmer convert one of our really slow CFHTTP laden scripts. The php script used curl for all of the HTTP handling. It ran so fast I didn't think it did anything. We're talking about going from hours of processing to a minute or so, doing around 100,000 calls to a google API.
One of the nice things about curl is that if you have problems with ssl sites you can set an option to ignore certificate errors.
The .NET rewrite also saw gains in performance over CFHTTP in CF, but not quite to the level of what we saw above.