I think Ridley Scott and Co have done a great job with this, the Technology looks very believable, Alien was too well dated but that is due to the Technology at the time... If we could have sent Ships into space back in the 70's to 90's no doubt Ridley Scott got it Spot on then...
Prometheus looked a bit to advanced, maybe not.. but certainly looked way more Advanced than the Nostromo given the Time Frame between ships (Prometheus class being about 30 years older).
I think Alien Covenant has got it Spot On Perfect and i would assume in 75-100 years time when we are flying people around Space to Mars etc then i think the Technology would be very similar to Covenant.