AbdulAlhazred
Legend
It really depends on the DM and the type of monsters you're fighting. OAs can be fairly common in some types of fights. Skirmishers, while they usually have OA avoidance powers, can often trigger them fairly often. A lot of skirmishers for instance gain a good bit by ganging up, gnolls for example. These types may well be happy to take standard OAs if it lets them get 2-3 creatures on the same squishy target. Now if your defender is built to dish out punishing OAs all of a sudden these things are a lot less of a threat. The same can be said for a lot of flyby attacking skirmishers. You may not actually get to USE your OA very much, but denying the enemy use of his best tactics is gold.
In any case, super optimized OA builds are moderately uncommon. Its a situationally useful build option and just doing really nasty damage on every hit is both generally more useful and has some of the same effect. Still, if you can fit it in with other aspects of your build then it can be worth doing.
Note also that wardens CAN switch from using DEX/INT for AC to using CON or WIS. They don't HAVE to do so. This means if you did want to make a high DEX warden you simply stick with DEX as your AC boost stat. There are other reasons you probably don't want to do that, but I think a STR/DEX warden could probably work fairly well, you'd just lose out on a few minor riders. Probably not optimum but doable.
In any case, super optimized OA builds are moderately uncommon. Its a situationally useful build option and just doing really nasty damage on every hit is both generally more useful and has some of the same effect. Still, if you can fit it in with other aspects of your build then it can be worth doing.
Note also that wardens CAN switch from using DEX/INT for AC to using CON or WIS. They don't HAVE to do so. This means if you did want to make a high DEX warden you simply stick with DEX as your AC boost stat. There are other reasons you probably don't want to do that, but I think a STR/DEX warden could probably work fairly well, you'd just lose out on a few minor riders. Probably not optimum but doable.