When me and my girlfriend got this it was already something new to us. She never really wears lip-gloss so that alone added extra intrigue. This lip gloss had the added benefit of being designed for foreplay though and has a strong raspberry flavor and scent to it. The description claims to make the lips more plump which I didn't notice beyond her lips looking a bit more defined and glossy. The gloss does tingle though and the effect of her going down on me with it on was wonderful.
On our first run through I mostly noticed the different feel of her lips on me. The gloss adds a little more friction, and combined with the anticipation it was a great experience. She did note though that she felt that the texture of the gloss was uncomfortable, and when it started to tingle she decided to take it off.
Overall while it was a great experience, it isn't going to make a huge difference in the bedroom. It is mostly great for adding an additional facet to the foreplay.