Of course the exchange between Alex and Grig before they take on the enemy ship in the asteroid is better.
Alex: It'll be a slaughter!
Grig: That's the spirit!
Alex: No, my slaughter! One Gunstar against the armada?!
Grig: Yes, one Gunstar against the armada. I've always wanted to fight a desperate battle against incredible odds!
(Alex just sits there, looking absolutely incredulous)
Alex: Terrific. I'm about to get killed a million miles from nowhere with a gung-ho iguana who tells me to relax.
Everything that happens with the Beta Robot back on Earth as Alex is off a million miles from nowhere. Test audiences liked the comedy of embarrassments Beta was endearing so the film-makers added more scenes.
For instance, there is Beta repairing his detached head and dealing with Alex's brother ("You're having a terrible nightmare. Go back to sleep.") just before he sees to his pained consternation an assassin landing. Then there is Beta finally revealing to Alex's girlfriend that he's an android, a claim proven when he is shot, revealing his circuitry and the only reaction he gives is a casual "See?" to the girl before he gives chase to the shooter.