My friend has the JSK, and in terms of being well-made and nicely printed, it's pretty great. The belt is removable (my friend hated it, so she took it off immediately), plus it has real belt loops so you can even replace it with another one. Another great thing is that the shoulder straps actually function and can adjust. The skirt fabric is pretty heavy. You can also buy it with a Tardis rosette for a little bit more, and I think it's a pretty cute accompanying accessory.
In terms of design, while I am not personally a Dr. Who fan, I can say for certain that it is most definitely the most well executed Dr. Who dress design to date. There have been a lot of very tacky attempts and this take is much more classy and subtle.
As for the price, since F+F is cheaper than most places you can get lolita, I'd say it's pretty worth it, and if you're a fan of the show, you won't be disappointed in your purchase.