Pros:
+2 free feats. Massive benefit.
Fighter Haste boost I Enhancement. Minor Benefit. Compared to Barbarian Damage Boost IV - this sometim provides a very small amount of a higher increase to DPS for the 20 seconds while it's active. And unfortunately you cannot activate both at the exact same time - there's enough of a delay that it's just annoying and mostly not worth it. So you pick one of the other. Damage boost for times your doing auto crits for bigger crits, or haste boost for general DPS. It's also just plain more fun to attack faster in DDO. And you can ofcourse statrt using these after your damage boosts have expired in very long quests.
Fighter Str 1 - You actually take a net loss in strength by doing this multiclass, a total loss of 3 strength with this 1 action point spent.
Fighter Stunning blow 1 - +1 DC to stuns, really not a +1 total increase for Dwarf/WF being that taking all 4 stun increase is very expensive in AP and generally not worth it, so think of it more as a way to save a few AP (It's 1 AP, while Dwarf/WF Tactics 3 is 6 AP) if you select one of those races.
Fighter Trip and Sunder also available, but generally not recommended except for builds specificly built towards maximum combat feat DCs
Cons:
-24 hitpoints at endgame (-4 from class, -20 from -2 con of mighty rage)
-No capstone. Capstone is: "Might", Grants +2 strength and now correctly grants +10% glancing blow weapon damage and 5% chance to produce special weapon effects in addition to its +2 Strength bonus. (A half-orc or warforged barbarian with all three THF feats, Great Weapon Aptitude, and Might will have deal 60% weapon damage with their glancing blows, with a 20% chance to produce special weapon effects). This is a significant loss for THF characters.
-No Mighty Rage. This means -2 strength and -2 con. (Overall loss of stats if you took Fighter Str 1 is -3 strength -2 con)
-Lower Rage duration. Since mighty rages +2 con applies to your rage duration, you lose a short amount.
-1 less Rage per rest.
-1 less point of damage reduction.
-1 less saves versus traps.
-1 less use of improved uncanny dodge (provides +6 to your reflex saves for 30 seconds)
-4 skill points total. (2 less per level)