IT ALWAYS DEPENDS ON WHAT YOU DO WITH IT!
This synthetic fibre sleeping bag is very well suited for camping, biking, festivals or kids. It is insensitive, dries quick and can be easily washed.
If you like to save some weight and when there is chance that its getting colder you will need downy feather. It isolates the same way having less weight. Furthermore the sleeping temperature is more comfortable.
So if it should be inexpensive and simple go for the synthetic fibre sleeping bag, for a better climate and more warmth with less pack size go for the downy feather.
If tours take place in moisty areas, you also should take the synthetic fibre sleeping bag.