A low poly count on assets intended only to be seen at a distance? Sounds about right. And, as has been mentioned, these were not assets you were currently meant to look at up close and I imagine that legs,should it happen, will improve all of these things. The engine is capable.
Here's a request in a similar vein.. Why can't I see station interiors with the free camera? I can travel through an open hatch and lose signal. I can't get the camera in to a docking bay other than my own, even if I attempt to follow the lift down. I want better responses to the slightly nonsensical activities I get up to.
As for the UE4 demo, looks nice but has enormous issues. Mostly a visual trick, leaving physics etc essentially nonfunctional. So while it looks fabulous, it's not terribly useful as a landable planet. Star Citizen is still no more than an expensive tech demo, it can't be used for honest comparisons. Is the tree pretty? No. But it's a perfectly adequate asset in it's current actual use case.
I recently built myself a new PC, held off on the monitor though - cheap Mexican beer-related stock issues. Radeon R7 290 to RX580 didn't seem like much of an improvement, until a few days ago when I did replace the screen.. Wow, that old monitor made Elite look crap. Same res and settings mostly, just better colour and refresh rate. The new onboard audio also seems to have given Elite a boost, not that the audio was ever shabby.