My major concern is that, each time I find a website to purchase/sell currencies, I end up finding a boat-load of horrible/terrifying reviews about their system.
Problem is everyone and everything can be shi* on. On internet anyone can write anything, often to slander business rivals.
So choosing which opinion to trust is really hard and thats why you can't find service without bad opinions.
Just use services which exist long in world wide web and that is their's best reputation.