Not too sure about rarity bro. Cos its all there available if you know where to look. For me it just seems like that there is a paradigm shift in service providers in the region.
Young, nubile, wet, wild and daring working girls used to be the domain of the Thais before. Not any more. Now they are mainly MILNF (Mothers I Like Not to Fuck). And worse. very SOP approach to sex. Thais going down the drain rapidly.
The mantle seems to be handed to the Viets. Whether because it's a later emerging socio-economic country... who cares. Truth is, the young, horny, eager viets are making my life very very happy once again.
They just seems more eager to partake in more intense sexual gratification. Big lovesss.
The PRC still have some quality. But perceptibly dropping their standards. Many thorns among the roses unfortunately.
Japanese babes also get my big thumbs-up. Now not expensive. You get true blue, very early 20s SYTs there to serve and please. You pay one hour for a service, they will honour that full one hour - as many times you like without question. Probably go next month again to see cherry blossoms and gets some young buds as well. Lols.