"Expansive, There is quite a difference."
Buying this depends on who you are. If you practically live off mid-grade red wines, especially if you entertain a lot, then this is certainly the product you need. But if you occasionally buy and serve wine, then there is no reason to be spending $40 on a wine Aerator, the wine is still good without it.
That being said, this does make quite the difference. The best way I can explain it to someone who has not tried it, is the difference between Soda pop from a can compared to soda pop from a fountain. You can't quite point out what makes it better, but it is so much better. Delicious with a certainly enhanced flavor.
If you do get it, buy a couple of bottle's of red wine, ranging from cheap to fine. I had 10 bottles of wine, ranging from boxed to one of the finest wines in my collection, all red wines, serving each of my guests two glasses of each, one aerated one not aerated. The taste test was blind, and by the time all was said and done, the aerated $5 wine tasted almost exactly like the non aerated $45 wine.
At first I had a problem with spending $40 on something like this, but after I realized how it made the wine taste like much better quality, I was so happy with the purchase