I actually own a Venus Sax, Flute (that I'm not using much any more. A friend is letting me borrow her Altus), and Picc. All of which surprised me in terms of playing. I wouldn't recommend them to a professional player, but for things like flute choir, community orchestras/bands, etc. I wouldn't hesitate too much.
http://maestromusician.com/music/Dvorak ... ances.html
I'm playing piccolo on the Slavonic Dance no. 10 for a reference. I'm not a great picc player, but it works well.
The MusicalWheel (the seller on ebay for Venus instruments in the USA) offers a return policy. You may think about getting one to try and returning it if you don't like it. If you try any ebay instrument, make sure they have that policy. I think a friend of mine has a DC Alto flute. She says that it's ok. She needed an alto flute, but didn't have the money at the time for a really nice one. She mostly uses it for things like flute choir (although I think she has been called for a symphony performance on alto once...not sure if it was this alto or not). She IS a professional player though, but normally doesn't get asked to play alto much.
Good luck on your purchase.
Also check into the cousin brands of bigger companies/better known Chinese brands (Brio, Azumi, Di Zhao, etc.) I played on a Brio alto that was great and it includes a lot of interesting extras (rollers on the thumb keys and D# roller for instance).