"In 4 season mode, the weight is very close to the Hilleberg Nallo 2...."
Indeed, and the Nallo is a very much more storm worthy tent. However, the usable space in the Scarp 2 seems a lot greater, and the Nallo2 has poor ventilation, making it less than ideal for warm weather. Also, the Nallo2 is not suitable for tall folks due to the shallow taper of the foot end...then there's the cost difference.
Having said that, we are not tall, and have made a summer mesh inner for our Nallo2 (which weighs 300g less), so we are happy campers ;)