Once again, I am exiled back to this part of the world, and from my experience, Dhaka is pretty much like any other cities that I have been around, Detroit and Cleveland come to mind. Sure it tends to be a lot warmer, and the monsoon can be a little bit of a bear, but otherwise I don't see a whole lot of difference. I now work for one of the local operators, and could give a little bit of my understanding of the place.
Dhaka prides itself on having an fitness friendly environment. When I am not strolling through the "diplomatic district", I am sprinting across two (five?) lanes of traffic, very good for the cardiovascular system. At times I have to jump the barriers between lanes, and dodge motorcyclists on the sidewalk. While there may be "fast food" somewhere in Gulshan, mostly we prefer to evacuate our bowels with the organic fruits and vegetables on the corner. As far as hotel food, I believe I saw my cook buying our restaurant food from the same food stall. No worries, it helps keep that BMI under 30. Word of caution - make sure that your precious bottled water has an intact cap, but really what's the big deal, most of the local water is loaded with arsenic. Hopefully arsenic kills bacteria, so you also have that to your advantage. Recapping, weight loss and fitness is a BIG advantage to Dhaka.
As for you single men out there, Dhaka has a wonderful nightlife. For slightly over $100USD, you could get a little beer buzz on at the Westin, followed by male hand-holding, with a stroll back to the hotel, ending up flirting with the only female staff member in the hotel, and realizing that she doesn't understand a word that you are saying. As for the married men, this place should keep your union intact, you can even invite your wife for a visit. After that, there should be no complaining from her about your extra-marital dealings.
Seriously, this forum is dedicated to professional pilots. Personally, my experience with the monsoonal weather doesn't worry me much. I would be more concerned with flying in other parts of the world. I fly Boeing aircraft, they are built like tanks. You fly these parts no different than other sectors of the planet, plan for holding, expect missed approaches, and fly accordingly. There should be no reason for anyone to deviate from from their flight plan without notifying the relevant ATC. I am barrelling down from high above, and I expect the aircraft that are holding or lining up on approach to do what they are communicating to ATC. There are coordination problems with Dhaka and Kolkata, why I don't know, but for the most part we are presumably under radar control. If you can't deal with a non-radar environment, you are not a professional pilot. And if you think of coming here as an expat, you will be the one scheduled to fly into the worst weather areas - deal with it.
So, come to Dhaka, it will be a good resume entry. Living here is cheap ($10USD/day), the expats all seem to have a great twisted sense of humour, and you will be a better pilot for the experience. As a contract pilot, you gotta be in the game, there is good money to be made if you are willing to sacrifice some good things in life.