Ian, I'm still kind of fond of the Aliens design. I thought ditching the dome was not exactly an upgrade, but eh; variation, it's all good. I mean if all of them had been identical we'd be sitting here typing about what a lost opportunity it was to introduce a bit of originality with each movie, etc. But yeah, the A4 and AvP stuff is, well, it's great sculpting, but I dunno, it's just not immortal design for me.
Leigh! Dumb question! You know the dome has that very slight central ridge, right? Best seen in Bowelrock's first front-on pic, above.