korat- zero "farang style" action. bunch of soapies/brothels in the city not hard to find with a quick google search. as for drinking go to dok mai cafe or happyland(same soi) which are outdoor thai pubs with pretty girls and live music. helps if you can speak a little thai but still ok if not. korat is a nice city but its a working/middle class thai city with zero tourists.
KK- small farang style bar area for retired expats, girls are old as well. nice that the thai nightlife area is next to it so you can check out a lot of different bars all in the same area.
udon- has an expat soi with bars. really convenient because its next to Central. bit more action on tinder and TF there as well. last time i was there (2months ago) few too many LBs around for my liking. girls tend to be older OR you'll see a few who are 18-20. not many in the middle.
