15% and 30% isn't that big of a difference really. You still have travel form for outdoors, and you're still faster than pretty much everyone else. One thing I think is a huge loss for feral is that there's no more infected wounds. The real benefit of feral, for me, was slowing an FC so that the rest of the team could gank them, rather than pure 1v1 DPS. There's still roots of course, but that's not a real substitute.
As attractive as displacer is, on a three minute CD, its usefulness will be minimal compared to wild charge, which I'm sure you'll use far more often, and find much more useful overall. Also, bear hug for 22+ guardians looks kind of interesting, especially for high HP bears. Stun and 30% of your health done as damage. That's 900 damage on a level 24 3k HP bear. That's pretty much a finishing move right there. Not F2P of course, but you know you're going to encounter them.
As attractive as displacer is, on a three minute CD, its usefulness will be minimal compared to wild charge, which I'm sure you'll use far more often, and find much more useful overall. Also, bear hug for 22+ guardians looks kind of interesting, especially for high HP bears. Stun and 30% of your health done as damage. That's 900 damage on a level 24 3k HP bear. That's pretty much a finishing move right there. Not F2P of course, but you know you're going to encounter them.