Well, if distances and sizes are "realistic", then most of space is going to be..well.. just open empty space. That doesn't tend to make for fast-paced action type adventure. SecondLife (at least from what I've seen of it) has a similar problem.. Many beautiful areas that are well built, ingenious and creative, but other than a few "hotspots" it's often like wandering in a vast ghost town.
Now, with Pioneer, it could be fixed with addition of some NPCs going on about their biz in at least some logical places. If, like Oolite, it had a fair stock of traders and raiders and cops in the most likely spacelanes, then there'd be at least places where there was higher levels of action. Pioneer is a WIP, though, and I think as missions and NPCs get added in, it'll get more interesting. I don't think the Newtonian physics will make that game many fast friends. It is more realistic, but it doesn't make for easy gameplay for the average new player who is looking to jump right in. The scenery and the smooth transition from planet surface to aerial flight to space flight are great. It's a beautiful stage set, now it needs plot and action.
Oolite, on the other hand, is very "hot" on action and especially with the OXPs, it has tons of missions and plots and subplots. Far more on gameplay than it is on scenery (though the eye candy has gotten pretty darn good too), Oolite is my usual choice when I have an hour and want some spacegame action. On a quiet night I'm more likely to play VegaStrike and explore. Pioneer, I can't really say yet, since I've just gotten to where I can actually land without crashing the ship into bits. Sometimes. LOL I didn't play FFE or FE2, so teaching myself how to actually fly in Pioneer has been a bit of a learning curve.
I did check the "space" sections of SecondLife to see if maybe there was a section that was an Oolite station or bar.. Kind of glad there wasn't, since seeing a bunch of Ooliters standing around in clothes shops trying on new clothes and hair for hours (which seems to be what people in SL spend a lot of time doing, from what I've ever seen) could have shattered all my illusions and left me scarred for life or something.

LOL
Sleep? Who needs sleep? Got game. No need sleep.