They're both the same mechanically. If you want to get down to it, Khem is technically better for tanking because he heals on mob death due to his stance. Xalek's stance doesn't have a flavor ability because it increases his armor.
The only other difference between the two is that Khem Val has an instant cast lightning punch and Xalek has a 1.5 lightning strike. Both have the same cooldown. Xalek also gets an unlisted ranged and channeled force lightning which does mediocre damage.
The problem with not using Mako(assuming you're not a heal spec Merc) is that it turns every fight into a DPS race. You have to burn down the enemy before they down you. This will not always work in your favor. Having Mako out, while causing you to deal less damage, usually means you will successfully kill any group engage. DPS companions are a gamble while Mako is consistent and effective.
The set bonuses are really minor. I'd go with whatever pieces get you to 30% crit asap. Other than that try to get the pieces that don't have wasted stat points on accuracy as it is no help at all in PvP.
The story [isn't new. It's boring and rehashed and certainly doesn't make you feel like a powerful Sith? Just because you liked it doesn't make it good. You're also implying that people spacebar'd through the dialogue sequences or weren't thoughtful with their responses if they didn't enjoy the story. That's a lot of assumptions.
They confirmed that the legacy system will unlock new races.
I'd say cathar have a high chance of getting added as a playable race considering they already have male/female variants, have hairstyle variants, can wear/show gear, and speak basic.
Yes it does! Bioware's logic was that they wanted you to use all of our companions instead of just one and switch their roles. When in reality we all just use one companion because it compliments our class/spec even if we don't care for that companion. In my opinion the previous system was way better.
You know he's destined to lose when he breaks away, but I agree. His inclusive stance with aliens made me sympathetic to his cause. He was a very forward thinking Sith.
Power Shot hits harder than Tracer Missile, but because of the Barrage talent there is no reason to use anything except Tracer Missile if Unload/Heatseekers are on cooldown.