A friend of mine owns this, so I got to see it up close. It's a very pretty piece of furniture and will hold lots of clothing (if you fold them), but won't hold a ton of the other items in Felicity's collection. The downside is that by folding all the clothes, they get wrinkled. The upside is that the piece is historically accurate to the best of my knowledge and it is well made (and yep, enormous).
Personally, I don't think it's worth the price I've seen some folks pay ($400, anyone?) but it is a nice piece of furniture.
I would recommend looking around for a large jewelry wardrobe that looks like it, but isn't, given that the official one has limited capacity for storage anyway. I got my fake one from the Bombay Co. (it's on my website in the siggy). It was only $100 after it went on sale and is (in my opinion) nicer than the AG one. It's also huge and heavy, but the upside is that I needed something to store my jewelry anyway and I don't like folding Felicity's clothes so I could care less about its potential for dollie storage.
If you look around, you can find very nicely built jewelry wardrobes that look like a clothes press after Christmas on sale for cheap at nice-ish furniture stores.