I don't feel that it's too soft at all! If you're worried because there are photos of people bending the toy in half, trust me, it's not that easy. And frankly, bending it that way is a bit disconcerting because it legitimately feels like you're going to break a real penis! I haven't had an hardness issues with mine.
I think that the softness is just right with the mustang. It really isnt easy to bend completely in half, plus why would you want to do that? Its perfect for rubbing those very sensitive places in both my partner and I so I think that the mustang would be a good choice. Its still soft but not to a point where you wont get pleasure.
VixSkin is fantastic if you want a toy that has some give and flexibility, while still maintaining its shape enough to manipulate easily and apply pressure. Granted, it's expensive, but I feel that it's very worth it (plus you can always save up your points instead of using cash!).
If you're interested in a dual-density toy but want something a bit firmer than VixSkin, try Tantus's O2 line.
VixSkin is amazing. I was originally worried about the same issue as we had previously used extremely firm silicone which at times was uncomfortable. VixSkin is the way to go. We found out what we were missing out on.