Speed, always, even in the 3-4. I run a hybrid 3-4/4-3 in 67. And my DE with lower strength has more sacks than my 100 ST DE.

https://mfn67.myfootballnow.com/player/902
https://mfn67.myfootballnow.com/player/845

Keep in mind that Shapiro missed two full games though.

DEs shouldn't be as strong after the next update see this thread:
https://mfn67.myfootballnow.com/community/thread/6/1923?page=1

here's the relevent quote from the thread

Yes, and I'm actually really concerned about DEs getting the nerf bat because the passing game already feels impossible to stop at times and getting to the QB seems to be the only way to get the offense off of the field.

Like most things in this game, the passing game is unstoppable or utterly inept. I wish I knew how to make things work consistently.

Gotta love having a defensive linemen in the QBs face on 3rd and long only to watch the opposing QB throw a frozen rope into triple coverage off of his back foot for 30 yards... lol.

And then on the next play drill the DT in the chest for the worst pick six ever.

So wouldn't 100 SPD 100 ACC 100 STR LBs and Safeties be the absolute best DL's once they got the Weight up enough for the STR to matter?

On the SPD they just blow by, and once the Weight is up they can push back when they do get engaged?

Is this JUST DE, or should DT be SPD as well?

I have used LBs at DE, DEs at OLB spots, LBs at safety spots... they all work well if their attributes fit what you are trying to accomplish.
That is, after they get their position experience built up.

I have had np switching LB's to RDE or even LDE and them finish with 30+ sacks in the season. If you want your team to be successful you need to keep pressure on the QB and make him throw early or take a sack. QB's will pick you apart without pressure. I believe DE is the most important position on D even over CB's

On this, speed kills on the D-Line (especially at end) and is really all you need paired with acceleration. I noticed you wanted space eaters in the OP, but they play really handicapped compared to the speed rushers. Speed is effective for ends because they break around the pocket easily but I find you need both it and Pass Rush/Run Stuff to be a force at DT.

In MFN6, which I assume he is talking about, Morbid made a huge trade for an outside linebacker. I ridiculed him for it at first but it ended up being well worth it. He's been one of the most productive players in the league at DE.

Also in MFN6 I have an end with 100 speed and 100 acceleration. He is only 80 overall with my current weights yet somehow he is one of the leagues marquee players. He has 116 sacks in the last three seasons (almost 40 per year) and is the all time career sack leader.