The scene itself is great, its positioning not so much. It was originally supposed to fit right after Ripley finds Parker and Lambert, but the DC puts it during Ripley's race for the Narcissus after rigging the Nostromo to self-destruct. It's a slow, unhurried scene which wasn't intended to go there, and damages the pacing.
More importantly though, the DC cuts some good footage ("What are my chances?" among others) and inexplicably redubs the extraterrestrial signal broadcast as electronic interference (when the actors' dialogue shows them hearing a voice). The added footage of the alien hanging on the ceiling before Brett's attack also spoils the scene, in my opinion.
There's still a lot of great stuff still on the cutting room floor for Alien - Brett's originally filmed death scene was very different to Parker's (head crushed between the alien's hands, a bit like in Blade Runner), and Parker is filmed struggling with the alien, which is how he inexplicably gets so bloodied in the final cut. There's also footage of the alien approaching Lambert, most of which is clear man-in-suit, but a couple of the shots are fantastic, and could work well with judicious cutting. And finally, they missed a trick by not correcting the most glaring fault in the editing, the transition between Ash's model head and Ian Holm poking through the table. All that's needed is a few seconds' cut to another angle to separate the effects.
The DC overall feels like a missed opportunity. The scenes that were added were done wrongly (or unnecessarily), the footage that was cut (which is actually more than was added, although most are snipped tracking shots) was in some cases important for atmosphere generation, things that really needed doing weren't done, and some of the more interesting cuts (though admittedly the cocoon scene was the best) remain unused.