The secondary you choose can really make or break your character.
For a defensive set, you should know, none of them give very much in the way of damage defenses or resists, and some of them are just plain BAD at everything. They all do all seem to keep you from suffering the effects of sleeps and the like, and they all seem to have a power or two that gives you a larger boost of strength for a short term on a long cooldown. I have not included those powers in the writeup values, only those that have 100% unassisted uptime. At high levels, some of the power sets can get 100% or close to it uptime on these cooldown powers.
ALL VALUES ARE UNENHANCED. SOs can double the values, IOs even higher.
This is designed as a simple apples to apples comparison for those with no access to a i25 character planner. My personal bias will show a more positive reaction to the sets with Endurance Recovery, as the ability to continually power attacks as fast as they will cycle is what sets the Sentinel apart from the Blaster.
BIO ARMOR
Bio is a decent set with middle of the road resists and defenses. It has a very limited health regen at 190%, and a 10% health boost. It does have a generous 150% recovery, and only costs 0.52 end per second to run the set toggles, tied with regen for the lowest. This set adds a lot of persistent physical changes to your body while those toggles run. It has an adaptability power that changes the way that some of the other powers function, like more resistant , more damaging, or more endo friendly ((The effectiveness of this power is still a point of debate. I have no first hand knowledge)). This secondary is usually considered a good choice.
DARK ARMOR
This is bar none the worst secondary and the secondary chosen by most of the people that immediately go out and bash the AT as useless. It is very toggle heavy, and for all those toggles, it gets less defense than Hover and Midline resists. It also is the only secondary with Stealth. It has a little more health regen than Bio at 240%, but no health boost. It has no added Recovery or max end, and those toggles cost 1.48 end/sec, the most of any secondary. It does have a self rez, and not a single other thing to recommend it.
ELECTRIC
Electric gives no defense but has one of the better sets of resists. It has 340% health regen, but no health boost. It has no enhanced recovery, but adds 10 points to the pool. It costs 0.94end/sec to run the toggles, one of the highest costs, but it does include a 20% haste buff. This is a middle of the pack set, good enough, but not as good as some of the others.
ENERGY
Energy has better than usual defenses but weak resists. It has no enhancements to Health Regen, Recovery, or pool sizes, costs the second most at 0.99 end/sec to run the toggles, and has nothing at all special about it. It has a 90 second CD/ 30 second active that reduces power costs and gives recovery... if it was a full time power, the set would still be less powerful than some of the others.
FIERY
No Defense and decent Resists, Fiery has no bonuses to Health Regen, Recovery, or Pool Size. However, it costs just 0.79 end/sec to run the toggles, and that includes a 10% Damage Increase, a constant 1.5% of health HoT, self heal, and self rez. It does have an extra attack power in the set that has some Recovery effects based on the number of hit targets.
ICE
Ice has some of the better defenses in the secondaries, and near immunity resists to Cold. No Boosts to Health Regen or Recovery, but it does have a 10% boost to Health Pool. It has a fairly low cost of 0.81 end/sec, and has a second "ABSORB" health pool that is used before the Health Pool.
INVULNERABILITY
Has the best resists in the secondaries (50% more than average), and some defense as well. No bonus to Regen or Recovery rates, but it does have a 10% bonus to the endurance pool. It also has a self heal to recover the damage that does get through its resists.
NINJA
NINJA has 16% Defense and 7% Resist to everything, which is better than most secondaries even without accounting for the lack of coverage holes. No bonuses, but it costs only 0.78 to run, and has a decent Endo Heal, Self Heal, and an AOE Cone Blind attack.
RADIATION
Considered one of the better secondaries, RADIATION lacks defense but has decent resists. No boosts, but it only cost 0.73 end/sec to run, and that is an impressive powerset with 20% haste, a self heal, and an Endo heal. Also has an Endo siphoning attack, that might give it the most Endurance to pump into 20% haste boosted primaries.
REGEN
REGEN offers no defense at all, and only 8.8 resist, which it gets late in the powerset. However it does get an second health pool in the form of an absorb shield that regenerates very quickly and takes damage before the actual health pool. It recovers health (once lost) at a rate of 365% with a minor 6% increase in the pool size, and recovers an extra 30% of endurance at a rate of 155%. Its toggles cost tied for the least at 0.52 end/sec and it has a Self Heal and a Self Rez. Considered a good powerset, best for those that take occasional small doses of damage, weak once the absorb shield is expended.
REFLEX
Has 18 Defense to all, the highest value for all secondaries. No Resists. No boost to Regen or pool size, but it does have a 30% boost to Recovery, for a total of 155%. Toggles cost only 0.78 end/sec, giving Primary power sets lots of Power while boosting them with 20% haste. Considered a Top Tier Secondary, slightly edging out Radiation as the best 20% haste secondary.
WILLPOWER
Considered the best powerset for its ease of use, great as long as you don't ask too much of it. It has a little Defense and a good enough resists, the best regen at 415% on top of a 20% health boost for even more regen, a 30% recovery boost, and it costs 0.83 end/sec to run the mostly toggle and auto powerset. If it all goes bad, has a self rez.
