This is our first glass toy, and we used it differently on both of us. For both of us the curve hits just the right spot.

For him:
I was new to anal play at the time, and the head of this toy was about as big as I could go, so I was glad the neck was more slender. Glass is a very smooth material too, so the sliding feeling was very pleasurable. I was new to prostate massages at the time too, and I wasn't sure how so much pre-cum came out of me, but it did. For getting used on my prostate, this toy is one of my favorites, and it's easy to sanitize, so we can switch players.

For her:
Since glass is so unforgiving on the cervix, I found that this toy worked best on my g-spot. But oh, how it worked! This toy delivers multiple orgasms every time. It was also a lot of fun to soak it in icy water for some temperature play.

This toy is not for rough play, and we found that it was easiest to use the beaded end as a handle (as opposed to inserting it). Lube+Glass=very slippery play

Glass is an excellent material. There are no ridges to irritate sensitive areas; it's perfectly smooth and good for sliding. It's also very easy to clean as it's completely non-porous. Glass also maintains temperature very well, so it can be cooled down or heated up for temp play.

The design is aesthetically appealing, and the shape helps it hit all the right spots! The curve makes finding your g/p spot simple and pleasurable. The beaded end functioned well as a handle for us, and the curve keeps it from slipping inside.
For her, the size is easy to take, but big enough to please.
For him, the size is a slight challenge for anal beginners, but the slim neck made the experience quite pleasurable.

Performance really depends most on who is wielding this toy at the time. We've had no problems with chipping or cracking; it seems like a very sturdy, well built toy. When play gets slippery, glass is sometimes hard to hold on to, but the beaded end fits in the hand pretty well.
We found that rigid glass is a good material for massaging both of our spots.
Since it doesn't vibrate, there is no noise roommates or neighbors could hear. Just be careful of how loud your own moans get!

Glass is very easy to clean with normal toy cleaner, or antibacterial soap and water. It came with it's own velvet pouch to store it in.