Ranger - favored terrain vs. favored enemy

Unearted Arcana suggests a variant giving rangers favored terrain bonuses instead of favored enemy bonuses.

The favored terrain gives +2 on Hide, Move Silently, Listen, Spot, and Survival in the chosen terrain.

Favored enemy gives +2 Bluff, Listen, Sense Motive, Spot, Survival, and damage against the chosen enemy.

Is this a fair trade? The skills make sense, but loosing the bonus to damage seems a big weakening. If a DM/Player wanted to go the route of terrain instead of enemy, what would be a good terrain-based bonus to take the place of the enemy-based damage bonus?

Quasqueton

The Horizon Walker's Terrain Mastery ability gives a bonus to damage against creatures who explicitly have the terrain type listed in their stat block.

So if your mastered terrain is 'Marsh', you don't get the bonus against creatures found in 'Any' terrain, but 'Temperate Marshes', for example, would qualify.

-Hyp.

It seems to be a pretty fair trade, as likely you'll be able to get those terrain bonuses more often to your skills and these bonuses go up by alot as you gain levels. So a 10th level range with have +6 to Hide, Move Silent, Listen, Spot, and Survival in forest terrain, +4 for Mountains, and +2 Underground. That's pretty good and something you're likely to have alot of the time as compared to the Favored Enemy bonuses.

I like to give the choice between favored terrain/enemy for the Rangers in my games and it works well so far. It's an even toss-up between the two, just depends what kind of character do you want more of: more the Hunter or Skilled.

Mixing it up as well can be alot of fun, for example a Ranger 10 has Favored Terrain: Mountains (+6), Favored Enemy: Giants (+4), Favored Terrain: Forest (+2). This guy is stealth personified in the mountains, pretty good in the woods, and is really good against Giants (especially in the mountains!). This has brought about an interesting aspect that seems to suit the Ranger style even better as you can combine the terrain/enemy bonuses to become a true anethema to one particular species in their environment which just shouts Ranger IMHO.

Though perhaps having them add like that is a bit much. Hyper makes a good point about creatures in terrain, but that could result in a favored bonus against many creatures, likely no one would want to take favored enemy after that.