Hi Teoh, thank you for the great review. I'm quite a beginner with watercolor painting and have been using Princeton synthetic brushes, which I love.
I am looking into investing higher quality of brushes for travel purposes.
I'm interested in getting Escoda travel set and would like to get your opinion on the series and size I'm thinking of getting for my level:

Optimo size 2
Kolinsky size 6
Versatil size 12