I wear this extender on my 24" Fine Spiga Chain... It's definitely not too heavy, doesn't slide down my back, and is totally worth the price in quality. No question. All women should have one of these in their jewelry wardrobe.
I bought the extender for a few of my necklaces that just seem to choke up on my neck. The length is perfect for what I wanted. Downside, it's so heavy that it falls down the back of my neck and I still get the choking feeling. I bought it to use on the love soar necklace and within minutes it starts falling down my back. Maybe if the necklace was heavier I wouldn't have this issue.
I have been looking for an extender, and the reviews on Amazon for some inexpensive ones demonstrated how insecure they were. They would break after 2 or 3 wearings; they were inexpensive but who wants to keep buying something just to use it once or twice? I decided to check the James Avery website and lo and behold, there was one, with the beautiful candelabra charm. Yes, this was more expensive than the cheap ones but oh my, as always, you get what you pay for, especially when you get it from James Avery.