Certainly the GT felt short. Fun but short. Once again the "sorting hats" is a boon and adds a welcome spice to one's participation in conversation with others, even if I don't really feel like being a Koko fits me :p
Though for me the feeling of "shortness" comes mostly due to the perception that it "barely" gets to contain two weekends (kinda sorta "starts on a Sunday, ends on a Saturday"), thus the times you can come home to participate while you are not already tired from the day is not only very limited, but also confined to the beginning and end of the event. Now, the structure of some events such as the VGM quiz helped alleviate that and also provided a good bit of interest, since we were basically getting the news that, in the least, there was some good new music to listento every day.
As one of the only two entrants to the Small Writing Contest, I feel a bit dismayed due to the low participation. Not that it's bad, I know better than anyone that even writers themselves have trouble forcing themselves to be up to creative stuff; but combined with the below it was more noticeable. I also felt the contest itself (and to a lesser degree the VG Trivia contest too) was not much advertised, which might have been a factor. For example the dedicated Fanfiction & Writing section, or the Creative Section as a whole, had no notable indicator or mention of it. As for other events I'm not sure if the VGM quiz was much advertised or not, but as a Koko I felt there was a notorious degree of mis, or lack of, communication into it that resulted in us getting zero points the first day despite having matched a good number of answers.
In terms of the GT itself I could see some benefit in stretching it to last 14-15 days if it was possible. I'm thinking a longer event is not really feasible unless the event hosters get a lot more support.
Of course I'm thankful to the organizers for managing to hold once again this yearly and characteristic PC event, and I feel overall a good job was done.
Finally, I support the addition of Necrozma Tribe as well.