Comparing ship designs of both games based on our current world / tech "realism" is pointless.
Ships designs of both games are based on in-game-universe "realism" and nothing else. The main difference is that both SciFi universes are different. While Elite is are more hard SciFi approach Star Citizen is more fantasy or "high" SciFi based.
Both games have complete designed ships, read: exterior, interior, systems and placement of those, center of mass, thrusters and so on. That you can not walk within your ED ship does not mean there is no interior.
David Braben talked multiple times about this, even on the new E3 material, and the concepts shown in this thread.
The visual design of both games is also mainly artistic choice and has no impact on "realism" of those ships. Yes, some SC ships where redesigned because of thruster or interior placement issues, but the overall aesthetic design was mostly retained.
But SC could use ED ships and made them work, if they wanted. And vice-versa, where is the point?
If we like those ships is still a mater of personal taste and which SciFi universe suits us more. None of those things is realistic in any way.
So don't get in wars with each other about personal taste masked as "but it's more realistic". Admit that you like this or that design more get over it.
Edit: I personally like the ED design very much. Because the whole universe is much more my taste. A can't stand SC's (artistic) design philosophy. I still see what they are doing with their ships and have to say that this is some very good work. But that does not mean I have to like it or that I think its more plausible than what Frontier does.