I found out a new thing at least for me (might have spoilers

[ToxicAngel12]

if you want to go totaly blind I assume you dont want to read it so... yeah

anyway I just played a reguler run but i wanted to have some fun by killing only the crew and not the ship becuse someone told me that it gives more scrap and stuff. anyway in my way i found a slaver ship and i tryed to kill all the crew... try it and u will see it is much effectivly than just surrender in my eyes

[Zaffre]

Yep. Killing off the crew of a ship gives you much more scrap than if you don't. One of the reasons I like the Slug ship so much is that you don't have to have a boarding party to get the rewards of killing the crew because your anti bio beam kills crew but doesn't do damage. Once you've got the shields down your bio beam does the rest. Your Slug crew members and the bio beam itself also give for some interesting choices in certain events. You know the infamous giant spiders? Using the bio beam you can kill them without a problem.

Killing the crew also gives you more fuel and you don't need to worry about shields as much.

[Derakon]

The bio beam is a pretty crap way to kill crew, though. Sending crewmembers over is much faster, which means you get shot at less (assuming you haven't managed to disable their weapons). You just need more crew and a teleporter. Of course the slug ship starts with 2 crew and no teleporter, so it's kinda stuck.

[icepick]

If you take out their weapons it's MUCH better than boarding since you don't have to worry about losing your crew. Ever. So I'd say it's not crap, just different.

[Derakon]

You don't have to worry about losing your crew unless you decide to take risks. Once they hit 25 health just retrieve them and send them to the medbay. If your teleporter isn't charged yet, then have them wander in circles until it is; the enemy AI can't really hit moving targets.

You have to take out both weapons and shields to use the bio beam effectively. With boarders you just have to take out weapons. And of course the medbay for both methods, if it's there.

With a max-rank teleporter you can even use boarders to sabotage Rebel droneships, which can be very handy since they tend to have absurd evasion ratings and way too many weapons. Your boarders won't asphyxiate before the teleporter recharges (though it'd be pretty close if you sent a Zoltan over, I guess). Of course the bio beam is utterly useless against drones.

[TheKillerNacho]

Personally, I prefer killing enemy crew with boarding parties but there is advantages to the Anti-Bio beam (I actually just finished a playthrough using it). For one, its a lot less devastating when one of your boarding team dies. When you lose a boarding party in sector 7-8 you're pretty much screwed but this isn't the case with the Anti-Bio beam.

Still, I probably prefer the Mantis ship with two bomb weapons as a ship to kill crew.

I've also found that two Breach or Fire Bombs aimed at their O2 system usually kills all enemy crew too, so there is that way as well.

[Gorlom]

if you want to go totaly blind I assume you dont want to read it so... yeah

anyway I just played a reguler run but i wanted to have some fun by killing only the crew and not the ship becuse someone told me that it gives more scrap and stuff. anyway in my way i found a slaver ship and i tryed to kill all the crew... try it and u will see it is much effectivly than just surrender in my eyes

Depends on the ship. you don't always get the same outcome.

[Saro]

I like getting a fast ion weapon or even two. Then if the ship has O2, just keep it locked down along with the weapons. If the ship doesn't have enough weapons to get through your shields, then a single ion weapon targeted at the O2 room is usually enough keeping both the shields and O2 locked down. Then I can just let them asphyxiate while I skill up my crew.

[OmegaJasam]

I guess the OP is refuring to the slaver ship specifically. That has an extra bonus for crew defeat