I have a Lois (DD2). And I do have to use the 'Superman' link quite a lot,as she gets called 'Louise',or usually 'Louis' when they see it in written form,eg,at the GP/dentist. I then have to say "Lois...it's Lois...as in Superman!"
Lois was a top contender of ours for quite a long time and the superman link didnt bother me at all, people would soon associate Lois with your new baby, the only thing that put me off was that people didntsay it correctly and t ended up soundin like lewis and it buged me lol
I would actually see the Superman reference as a benefit. As Lois is not a very common name, it'd be useful to be able to say "as in Superman" whenever someone hesitated over the pronunciation or spelling.