(Note: This reply is going to go far beyond your post. Not all "yous" are actually you...but, a general "you.")
It does sell itself as a "prosthetic vagina." (Yes, I had to get a load of what this thing looked like). It Is a vulva (though it does look like it has a simulation of the birth canal for various purposes). Though, technically it is neither a vagina nor a vulva...nor a uterus...it's a toy. I would not call my strap-on a penis. I call it a strap-on. It's a toy. I'm fine with it being a toy. If I paraded around on the street proclaiming to understand the male experience because I wear a strap-on, I would be considered off my rocker. It is also off your rocker to proclaim that a plastic/latex/synthetic toy is the same experience as womanhood. I also laugh at the bra-burning feminist stereotype...but, damnit...it makes me mad.
It's like what I was saying with the "sissy CD" thing. Yes, that portrayal of women is totally anti-feministic and offensive. However, I wouldn't judge anyone for it as long as they had it in perspective. As long as you don't REALLY think that women should act or behave like that, I could care less what you do in your bedroom. If you are a drag queen, acting like a clown...go for it and make the$$$. But, if you think that this is REALLY how women should behave and because they aren't, they are less womanly....you are wrong. If you want to wear random prosthetic genitalia for the heck of it, go for it. I really don't care if that's what you're into...as long as you aren't hurting anyone else, wear whatever the heck you want and play however you want. ...BUT, don't tell me what a beautiful experience it is for you to load up your fake blood and sit on a Kotex. Don't tell me that you understand womanhood. Real menstruation is a very weird aspect to womanhood...but, trust me on this...it's not womanhood. When women go through menopause, we don't magically go *poof* and turn into pumpkins. We're still women. Women who cannot menstruate (I was actually in this category for a while when I was running track), are still women.
When the fantasy or whatever becomes reality and you are equating your experiences with a group of people that you really know nothing about, that's when it becomes anti-feministic. And, this is when I (as a feminist) get sh*tty with said individual. (Or, I become so taken aback that I don't know how to respond). See OPs analogy to RPing a soldier versus actually being a soldier. Would you tell a war veteran that you tried on a WW2 uniform a few times and held a gun...so, now you know what it feels like? No. That's insane. And, I find the equating that manifests on this site equally insane. (Though by a loud minority).
Anyway, those are the main things that really jump out at me as really bothersome as far as anti-feministic. I don't really think the sissy CDs are a minority (I might be wrong), but again....nothing wrong with it if it's a game at the end of the day and you really aren't believing that's how all women behave.
And, that's what I feel the OP was getting at. CDing isn't wrong as long as YOU own it and don't use it as measuring stick for the ideal femininity. Most CDs are on the epic journey to achieve ideal femininity and look like the ideal woman when dressed. Well, I can tell you right now that so many are literally failing at it miserably because they haven't the first clue what femininity is...and, I can also tell you that you won't find it inside the perfect dress or up inside of a synthetic vajayjay.