Well, as a service to you lovely people, I bought the bundle at the bargain price of all the other prices added up Some small spoilerish things but it's not like there's a plot to spoil.|
Overall, I should say that the levels generally feel like they were designed for this mode. I know they obviously were, but they don't feel like levels missing from the main game, and I'll definitely be playing them a good bit more.
Gold Rush Pack - This was probably my favourite of the 3. There are coins, always coins! So many coins, so much to collect, so it can be a challenge choosing the best coin path. Score chasing for this one should be good as there are plenty of little secrets hidden to optimise your coin collection. Pure gold chasing fun, plus it'll speed up your quest for a million. I'd definitely recommend this pack.
Coin Challenge Pack A - Not sold on this one. Some nice challenging sections (especially in the 3rd level), but this one is the closest to feeling like normal levels. The time limits are a bit tight, so it's not like you can just chill out, but they don't feel as well tuned to the whole Coin Rush concept. Still some nice original touches, but I really couldn't recommend this pack.
Nerve-Wreck Pack - This is a proper challenge! So much so I went for the White Raccoon option, yet it's STILL hard! In fact the second level in particular is a little harder.
The first level is almost entirely of coins, with a P Switch. One you start the course by hitting that switch, the race is on! You really have to leg it, and unearthing the other switches on the way to extend the duration can get quite tense. Even the Raccoon Suit is of little use most of the time.
The second level is rendered a lot harder with the White Raccoon Suit as it's a lot of long stretches of lava, with the intention being you bounce across enemies. So if you don't have at least a normal Raccoon Suit, you're going to have a bad time!
The last level is one of the ones that starts with a cannon firing you out so you can't stop, and your only platforms are Bullet Bill's. I have to admit I didn't reach the end.
This pack is definitely the best one for the Mario faithful who usually find it all too easy, as it's really challenging. I'd probably recommend this most for long-term fans looking for something to really test them.
So in summary, the Gold Rush is the most fun, Nerve-Wreck the most challenging, and Coin Challenge the closest to the original game and probably not worth your hard earned cash. Any specific questions, let me know