I actually think that SMG1 had some better, more difficult and involving Purple Coin Challenges than SMG2. Those really tested your platforming skills as well as your nerves. Nonetheless, these were entertaining as well so I ranked them.
Purple Coin Flip 'n' Sprint- Just the way I like them: fast paced with precision movement required. And it also forces you to efficiently use the spins.
Tall Trunk's Purple Coin Slide- Same stuff. Requires a good strategy and flawless execution.
Luigi's Purple Coin Chaos - Maybe I like this one because this one is a breeze compared to the one in SMG1, but it's really fun. You still have to map out a path and execute it perfectly.
Purple Coin Beach Dash - Short, but very fun.
Purple Coin Shadow Vault- Actually, not that difficult. Just work your way outside-in. I even got hit 2 times and easily made it the first time.
Purple Coin Spin Speed Run - Pretty decent challenge as well. You really have to learn how to make jumps with the drill and use the gravity the right way in order to complete this one.
Purple Coins On the Rainbow Road - I think this one is fun as well, only a bit difficult since you do not have a lot of time. I dislike however that a few times you really have to hit the brakes to collect enough coins. It really slows the action.
Bulb Berry's Purple Coin Glow - Nothing special, just collect al the coins.
The Adventure of the Purple Coins - It's not that difficult, and requires a lot of concentration. It just wasn't really fun.
Maybe I'm crazy, but the path for Luigi's Purple Coin Chaos is almost identical to the one from Luigi's Purple Coins. At least, the way I do it. The trickiest part is probably a tie between accurately collecting the first 30 coins, and the final 10 coins when sometimes I might screw up and leave a purple coin hanging over a disappearing green platform. Not a fun moment, haha.
I think you may be right that the purple coin missions in the first SMG probably being a tad better overall. I mean, there's still a good chance I might mess up and die in most of those stages, whereas I'm well on my way to memorizing the ones in SMG2. The only exception is Purple Coin's Beach Dash since me and the dash pepper aren't the best of pals!
Oh and I probably should have ranked Bulb Berry's Purple Coin Glow lower since now I find it way too easy and short.
Yes, I also take roughly the same route with Luigi Purple Coin Chaos as with Luigi Purple Choins. However, some difficult jumps are not necessary anymore and the rotating tiles are also gone. Risk of dying because of the level design is lowered. You just need to execute. I completed SMG2 twice, the first time it took me one try to beat LPCC, the second time three tries. While I still have troubles with LPC. But once you mastered this one, LPCC is a walk-in-the-park.
I forgot to mention: even though SMG1 has better Purple Coin Challenges, I do not like the time consuming ones, like Honeyhive Galaxy and especially Seaslide. I think most players agree with me. I actually died in Seaslide once after I collected all the 100 coins on my way to the star. Just fell of the Island. *Epic Fail*
Most gamers do agree with you concerning Honeyhive's Purple Coins, though I'm one of the few that really loves it. There's one part where you have to jump across a few honey-sticky platforms that affect Mario's jumping- I've learned to do this part first and the odds are really good I won't die after that. And yeah, I know which jump you're referring to in Luigi's Purple Coins- in LPCC, there's only a few coins in the air at this section so it's easier to line up Mario's jump and grab them.
I play hopscotch on my driveway despite being a grown man just for the opportunity to touch one magical purple coin that may form straight ahead!
The full moon the other night was amazing watching it through binoculars, but imagine watching 4 purple coins twirl around the moon all night?
Would those coins be around the "boo moon"?
Yes! And when Mario stands on one side of the moon, it droops down, haha.
Picture Mario and Luigi dancing on stage with a floating pizza twirling between them in the air, enticing the brothers to dance harder! Oh and rank the purple coin missions :p
They are all easy except for tall trunk slide on that I almost always get 99.