I also went to Cambodia last month after 18 years. 18 years ago there wasn't even an ATM machine. Only a few old cars and a lot of old motobikes. Now on every corner there is an atm, the city is full of new cars and new motorbikes. now there are also Streets full of entertainment bars where you pay to talk to woman (or more).
Phnom Penh was still dirty, filthy, stinking city. They realy don't know how to make that place much better and keep tourist that have money. The nicest area is full of cheap massage brothels and bars. Bangkok can be dirty, but Phnom Penh is realy dirty. But easy with visas. Also you have Happy Pizza Pizzerias. There you can buy pizza with marihuana
You can also go in the kitchen and buy only the herbs so you can make a happy pizza at home. That is another reason why Cambodia is popular with backpackers.
To Sihanoukvill or Siem Reap i go probably next month. What i have heard the Chinese bought all the nices places at the beach in Sihanoukville the last years and put them down to set up things for the Chinese tourist. I will see myself soon.
But it all depends, if you have enough money you could built a nice villa with seaview and some studios to rent out for 200.000 USD somewhere in a nice condominium in south america like Brazil, Mexico, etcetra. But there must be places in Italy and Spain where you can do that also. In europe i would consider the canary islands also.
I am also looking into Africa to stay there some months. But haven't seen a country that has my interest. Maybe i just go to some easy countries first like Cape Verde.