I think Spring Circuit and Sunset Beach quickly became classics as soon as they came out, just really polished layouts with good and clean visuals no-questions-asked.
Spring Raceway (Spring Circuit's remake) has lost a bit of the charm from the original, though.
A lot of my gripes are visual - the level is just less visually interesting, due to some landmarks being pushed away or removed, and some shadows from the rocky formations are inexplicably gone (like the one right after the 180º at the start), as well as the server advertisements which made the level pop more and feel less artificial. The music change also made the level feel a little less upbeat than before.
There's definitely improvements layout-wise, offroad cuts are a lot more accessible (lines to take offroad cuts felt a little awkward before), but the red spring panel jumps are less interesting than before. In Circuit's, they served a purpose by allowing the player to *extend* their drifts and get a red or a rainbow miniturbo, as well as serving as prime trapping spots in netgames, which is interesting due to risk-reward. In Raceway, they mostly serve as a way for a player to *start* a drift, get a blue or maybe a red miniturbo before releasing, and that's pretty much it. I also miss the long straightaways at the end from Circuit a lot more, they were just pure item slugfests, although just as much people complained about it being an item slugfest in netgames iirc, so maybe I'm wrong. Oh, and do look at the Discussion tab for some blindspots you could fix.
Given that both Spring Circuit and Raceway are both available, it still feels like a "two cakes" situation for me, but I believe Raceway could be improved further by taking cues from its predecessor.
The pack is still really good/5.