After taking a look at all the screens, I ended up going with Magiska Dalen as well. Panther and Buzzard County Mine Train were tied for second. Betri Langskip was so unrealistic, I couldn't get past it and appreciate anything else. I'm all for a fantasy coaster, but even those need to be somewhat believable.

Magiska Dalen
The detail of this entry is stunning, especially in the architecture and landscaping, but my favorite detail is the curvy monorail/steeplechase fence. Though not much could be improved regarding the quality of the entry, I will recommend that, since Build It is a coaster competition, you take enough images to capture the entire layout of the coaster. Two rounds ago, one of the most solid RCT2 entries we've ever had lost because voters could only see part of the coaster. The part we can see is delicious Arrow goodness, but after the second corkscrew, it becomes a bit hazy. Still clearly the strongest entry this round.

Panther
Definitely a solid layout, and with some landscape fine-tuning (shrubs in addition to trees, more terrain paint variation), this would have winning potential. The large rock at the top of the lift hill is nice, and I think a few more rocky patches would enhance this even further. I also suggest you paint your trains rather than use a default color scheme. Most players won't notice since RCT2 default train schemes are somewhat realistic to begin with, but it's a subtle way to give your ride a further sense of identity.

Buzzard County Mine Train
It's rare to see two entries in a round that are almost full-CSO, and though this one isn't as strong as the other, it's definitely off to a nice start. For the terrain, the jagged rocks work to an extent, but it would more natural with some smoother, larger rock formations rather than every single square doing something different. CS foliage is wonderful to work with, and you're actually using my favorite foliage piece, the square grass base. This is an extremely versatile object, and it can look stunning in patches of 2-3 different colors. You might find that the landscape will look more natural using this object in patches rather than just quarter-tiles. In addition to the two main foliage colors you're using, regular olive green mixed in would allow the foliage to pop even further.

Betri Langskip
Aside from the uncomfortable inverted portions and the awkward ending, this layout isn't too bad. There's only the one launched section, and it's at the beginning where it belongs, so it's definitely an improvement over past entries. Scenery-wise, it could use much more polish, and if the rockwork were as strong throughout the area as it is in the first few seconds of the launch, it would make that much of a difference. It may help considerably to study the landscapes of winning entries from 2013-2015 (RCTgo's Golden Age of RCT3). The most important suggestion I have to give you, however, is paint your trains! This is important for all RCT3 players to remember, as this game only has one default train color scheme, and it's recognizable from a mile away. You're definitely improving, and if you can match the quality of your entries with the quality of your ideas, you'll be a nearly unstoppable force in Build It!