I don't like freeform for a reason not listed; because it's just too arbitrary for me. If I want to do something, I can do it, unless the person in charge tells me I can't. So either I'll always succeed at everything I do, or I won't because someone decided I don't, for whatever reason.
Generally, I'm not the sort to be doing things I don't believe my character should be capable of, so when I can't do something, it can feel like arbitrary failure. Failure because the GM wants me to fail. In an ero game especially, it tends to be "you failed because the GM wants to rape your character" which rubs me the wrong way.
So basically, in theory I would be fine with a freeform if it had a GM I trusted. But I'm not exactly the trusting sort.