No direct experience here and, no offense, nothing I even want to take a chance on in the first place. That being said, if you're potentially going to be exchanging bodily fluids with people who have a likelihood of HIV infection, I don't think there's really much doubt that it will be necessary to have safer sex. From reading up on Truvada, the most common side effects don't seem to be too bad (although the less common and more severe ones do look a little scary), something I am sure your doctor will cover in detail. The real sticking point is the cost - it's expensive and the approved generic version (which in Canada lists for about 1/2 to 1/3 the cost of the name brand version) isn't due to be released until next September. Even if the generic comes in about the same price as it goes for in Canada, it's about $400 a month...depending on how much may or may not be covered by insurance, that could be a significant financial commitment.
As for transmission rates, one study says that those using Truvada as a preventative measure experienced a 51% reduction in transmission rates compared to the rest of the population - since that isn't 100%, I would still strongly recommend barrier methods in addition to the medication. I understand completely that it can be easy to forget condoms when you're in the heat of the moment but HIV is forever and even with all the treatments available today it's a deadly, incurable disease. A friend of mine has herpes and that's something that, while obviously less dangerous than HIV, is going to be with him forever...if you think it's hard to be HIV-negative in a place where there are a higher-than-average number of HIV-positive people, imagine how hard it would be to be HIV-positive literally anywhere.
It should also go without saying that regular and, indeed, frequent STD testing is paramount, especially if you're not sticking with a single partner. HIV can be a nasty one that hides from tests, but it's also not the only disease to worry about. Anyone who hasn't been tested, doesn't want to be tested, or is hesitant to share their results is someone you probably don't want to be with anyway, HIV or otherwise.