Bumping this because i didn't want to make a new topic for this observation, but did anyone else think that 8-K was way way easier than 1-K?

That's just the impression you got, because by the time you reach 8-K you've practiced your skills to the point that everything seems to be much easier than during the first few hours of playtime. Play both levels in mirror mode and you'll see that 8-K is the harder level out of these two.

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Regarding my question to Resident_Hazard, I've found the answer coincidently in a thread from 2008. He really is claiming that Metroid Prime 3 is dumbed down based solely on the normal difficulty setting which is an easy mode that wasn't present in the first two games. Normal in Metroid Prime and Echoes is the equivalent to veteran in Corruption, but he barely touched that (didn't even play up to Mogenar).

Claiming that a game is easy based on easy mode... well, that's not conclusive proof.

If I'm reading you right, you didn't think Prime 3 was especially easy.  Now, I'm a huge, huge, huge Metroid fan, and I spent ample time loving the crap out of Primes 1 and 2.  That said, those games challenged me to love them with some of the most punishing gameplay imaginable.  I was routinely beaten to a pulp in both titles, spending hours on singular battles.  The Omega Pirate was hard enough on regular mode in Prime 1.  On hard mode, that boss might as well have been a certified rapist.  Prime 2 was even harder, and I was stuck on that one--the final sequence--for a year on regular mode.  Only coming back when I was good and brave enough (later, I discovered by accident that if I "restarted from last save" after the Emperor Ing, I actually started after that 45-minute battle and didn't have to do it again to face Dark Samus 3--a year of frustration because I thought "restart from last save" meant fighting the Emperor Ing again!!). 

Suffice to say, I spent a lot of time being killed over and over again in Primes 1 & 2.  Enemies, bosses, stages, etc.  Everything was just so immensely challenging.  Then Prime 3 rolls around, and enemies drop like flies, bosses are all push-overs, and puzzles aren't quite as challenging.  It wasn't the controls that made Prime 3 easy, it was Nintendo making Prime 3 easy that made it easy.  Fewer enemies, weaker enemies, weaker enemy attacks, simpler bosses--everything.  The game was clearly intended to be "blue ocean friendly" with it's much lighter difficulty.  I think I died maybe 3 times throughout the whole game, and I don't think I did once on any of the bosses.  Again, I think I lost at least 20 lives alone to the Omega Pirate in Prime 1 on either difficulty setting. 

The commercials indicated as much, having Metroid Prime 3 advertised as being played by regular people rather than hardcore gamers.  As if Nintendo was saying, "See?  Anyone can play!"  Which, of course, they were.