I remember when Tempest Spine was quite tricky because the blackguard elves had really high AC and you actually had to spec to hit them (i.e. use +5 weapons instead of your +2 holy).
Then one day the ACs on all the mobs were nerfed, and now pretty much everyone runs around with power attack on, all the calculations on dps I see on the forums assume you 'hit on everything except a 1' - so what's the point of having a high to-hit?
With the addition of the Kensai prestige enhancements, Kensai become warriors who are forced to specialise in attack bonus boosts and weapon focus feats to give increasingly useless to-hit numbers given the current level of ACs.
Please make the Kensai set of enhancements worth something vs the barbarian dps machines by introducing a set of mobs with very high ACs (in the 50s or 60s). This will also make people play more tactically and use destruction and sunder, and indirectly help fighters who have specialised in these feats.
Cheers,
Garth