They are based in China so take that as you will. They are very hit or miss based on past reviews that you can read by doing a search on the forum. Some people have a great experience and others don’t get what they paid for. It’s similar to the third party stores on Amazon that are hit or miss. One consistent running theme from the past reviews is that seamstresses will not touch their products to do alterations.
We got our bridesmaids dresses from there for our ceremony in July. The dresses were really nice. However, we did have to return two of the dresses due to size, and it took forever for it to be processed. So, what helped us was that we just ordered the replacements while we were waiting on the returns to be processed. So, it worked out for us, but do not recommend if you are not able to allow a 3-4month window. I say this, because shipping took forever! We ordered originally in early Jan. and received them in early Mar., and if you have to do a return and can't just buy the dresses before your money is refunded that can take 3weeks; in our case it took 3weeks. However, if you're not a last minute type of person, I would say give it a try.
I've seen some for sale on stillwhite and other used clothing or wedding dress sites. That's a good way to see their dresses and their quality and sometimes even the comparison between the original and the reality. I've read it's usually close enough to the photo that people are generally happy because for the price you have to expect more average quality and slight changes, but that overall it worked out. Google image search jj house wedding dress or used jj house wedding dress for sale too. That's a good way to get a realistic idea of what you're getting into as well. Research! Research! Research!
We got our flower girls dress from there and it was a really good quality dress, which I was very nervous about since the reviews were so bad. I just couldn’t find a dress that I liked more than the one I found there.