Mass Effect 2 questions.

1. It depends on the power.

For example, Dominate and AI Hacking's area evolutions are counter-productive. If you take the area evolution, then multiple enemies can get shields/barriers, meaning you just end up with a group of enemies that cannot damage or kill each other. Singularity is also better at Heavy Singularity instead of Wide Singularity. You can go either way with Reave.

Area evolutions are generally better on the other powers. It may also depend on your game difficulty.

Generally, area evolutions are better for the following reasons since you can hit multiple enemies at once (even though you will not always hit multiple enemies at once). This means you can overload the shields of multiple enemies, freeze multiple enemies, lift multiple enemies, and so on.

Game difficulty can also play a factor. On Hardcore and Insanity, for example, Area Overload is just fine for stripping shields off basic enemies, but Heavy Overload -- even with maximum power damage bonuses -- will not strip the shields of stronger enemies. So the better strategy is to stick with Area Overload to (potentially) affect as many enemies at once as possible.

Now on Veteran and lower difficulties, only elite or stronger enemies have defenses, so defense-stripping powers like Overload and Incinerate may be better off with Heavy versions to fully strip the defenses off theses enemies.

For duration-based powers like Pull, Cryo Blast, or Neural Shock, area versions are generally considered better since the extra duration from the Heavy versions are generally not worth it. Basically, the duration at rank 3 of these powers is considered good enough, so the area evolution is considered better, because again, you can potentially hit multiple enemies with it.


2. All research projects are cumulative, but all ranks of the project have the same value. For example, all assault rifle upgrades are +10% damage. So three assault rifles upgrades = +30% damage for all assault rifles.

So when you see +20% assault rifle damage on the upgrade screen, that means the upgrade will give you a total of +20% from all assault rifle upgrades (two assault rifle upgrades at +10% each upgrade).


* * *

Hope that helps