No, Slayers trade off the Defender role abilities for a Striker bonus damage feature. That, at least, is the standard trade off between roles. They trade their dailies and any chance at a real Nova without MC/Hybrid shenanigans for a minor increase in defenses over a Barb.
Dexterity modifier to damage is the basic bonus damage feature. This scales at just under the same rate as the average extra damage from the PH ranger's Hunter's Quarry (minus feat enhancements). The increases to 2 + Dexterity modifier at 5th level, 5 + Dexterity modifier at 15th level, and 8 + Dexterity modifier at 25th level are (IMO) the damage bonuses in lieu of daily powers.
Yes, I also know when you are making a poor trade. In this case, you're making a very poor trade.
I think you are under-valuing the slayer's damage bonus. It really is (IMO) a striker damage mechanic and a daily power replacement rolled into one.
Yeah, "Only miss on a one." It annoys the crap outta my DMs when they see me roll a two and I say AC21 at 5th level. Why are you even trying to get your Thief in melee range? Halfling Shortbow Hunter, Drow Ruthless Hunter = "Hi guys!, I'll just stand wayyy over here and barrage them to death!" thats before RM for snap shot and other tricks to add in multi-attacks.
I admit to being curious. How are you hitting AC 21 on a roll of 2 at 5th level? How often can you do it?
Yes, they are ridiculously easy to optimize since they broke the standard power assumptions from 4e. MBA's were set up to be little used, off action attacks that you only made when you couldnt do anything better and were supported as such. E-martials, and Arcanes now, broke that mold and enhanced the MBA to encounter+ level equivalents with absolutely no brakes in the system to prevent a PC from piling on e-enhancements and 4e enhancements. The worst part is, they keep compounding this mistake. Now we get MME which takes an MBA enhancer(PA) that already hits encounter+ level equivalents with WS and throws even more benefits on top.
I will admit that there are some good synergies. I'm not at all convinced that they lead to "broken" levels of good, though. Even the feats in Mordenkainen's Magnificent Emporium that enhance
power strike don't strike me as being overpowered at first glance. First off, you are spending a feat to get the benefit. Second, you are enhancing an encounter-level resource, which means it won't be used as often. As always, you need to evaluate the package as a whole, and not declare something to be "broken" or "overpowered" by fixating narrowly on one element.
Woefully underpowered. The powers give up very useful effects on a hit for minor situational bonuses as an effect most of the time.
As I mentioned previously, a Sun warpriest's powers tend towards protection, healing and restoration, and a Storm warpriest's powers tend towards buffing damage and increasing mobility. None of these seem to be situational to me.
Drastically lowered top end usefulness for a supposedly raised floor. Yes, there are a few good powers in the Warpriest list. You just hope you get one good one for every POS you get stuck with.
As I mentioned, evaluate the whole package. Don't fixate on the warpriest's Utility 1 powers which are mostly flavor. Compare their at-wills with a templar cleric's at-wills, their encounters with a templar cleric's encounters, their dailies with a templar cleric's dailies, their channel divinity powers, and the 5th-level domain features with Healer's Lore.
Your Channel Divinity options are crappola in most cases, WotC seems to have forgotten all the decent ones they had released and done a major backtrack on the power levels.
The templar cleric's
divine fortune grants him a +1 bonus to an attack roll or a saving throw. The Sun warpriest's grants a saving throw with a +2 bonus to himself or an ally, and the Storm warpriest's grants extra lightning damage to a melee attack (+4 at 1st level, increasing to +6 and +8 at 11th and 21st levels) to himself or an ally. I don't consider these powers to be useless, and frankly, they look more "leader-like" than the templar cleric's.
As for your wonderful Class Features? Ever heard of Ritual Caster? You know its great that a Warpriest can Raise Dead his allies for free...of course a Cleric is just better at preventing them from dying in the first place.
The templar cleric gets Ritual Caster as a class feature, and the warpriest gets two daily utility powers. This, to me, is another trade-off. And once the 5th-level domain features kick in (which I had omitted in my earlier analysis) the templar cleric's Healer's Lore doesn't seem to be that significant an advantage.