The worlds are pretty expansive (well, the later ones at least) and the quest hubs are numerous and fairly spread out so even 'shared' planets you don't see a ton of the enemy on in my experience. Some planets are completely inaccessible by them, like the starter planets and I think Taris/Balmorra as each faction gets their own 'instance' of those two.
Cleared Denova last night, the final boss was actually easier than expected. When reading about the fight it sounds like it's going to be much longer and more arduous than it actually is, so I'm not sure if our DPS are finally getting their act together or if that's just symptomatic of 'normal' mode. Either way, looking forward to hard mode and the 'story quest' that you complete there has a pretty goddamn cool cutscene at the end of it, it actually makes me want to know what's going on and curious about the potential story behind future operations.
I would love to see some larger scale bossfights, (though after clearing the instance it does make more sense to save something like that for more than 'just' Kephess) something like Lady Vashj or Kaelthas in Tempest Keep. One thing I thought WoW did actually do very well was create those long, intricate, and ultimately very rewarding encounters.
Also really appreciate the combat logging. It's still a little wonky though it's hard to say whether that's the fault of the parser or the log itself, but whenever we 'merged' ours on MrRobot last night we ended up showing incorrect numbers of attempts for some encounters and the 'threat' calculation seems to be way way off as well as a few other bugs, but it's nice to finally see some idea of damage dealt/damage taken/miss rate/etc.