Yeah, whenever I am reminded of the Mustang the first word that comes to my mind is COMFY, that magical place beyond just being comfortable, I agree it is wonderful for thrusting. The softness of the head keeps that "gut punched" feeling from happening and the corona of the glans gives you a wonderful indicator of when you are about to fully remove it from your body.

But, I will warn anyone that because the head is so squishy it can be inserted into a rather tight orifice with relative ease. And when that orifice relaxes the head can expand and create a very sudden feeling of fullness (like it suddenly inflated) which might be unpleasant to some. But if you are relaxed on the initial insertion you probably won't notice this. It is something I learned the FIRST time and definitely remember.

From what I've heard, VixSkin's outer layer has more give than O2's (I don't own any O2 toys, so I can't be 100% sure), so there may be something of a trade-off.

I moved up to the Tex from the Spur without much trouble, so the Mustang (which shares a circumference size with the Tex) is probably what I'd try out of these... although it's a tough call, since I want to try the O2 Mark, as well!