FX Choice seems to be the only US forex broker that offers the MT5 platform. I have two question: 1) Has anyone heard any nightmares about this broker? (ie: money deposited and ...hm.... I was going to say "money deposited and never seen from again" but then that's a very common happening.) 2) Is there a reputable (as reputable as FX brokers go) FX broker that offers the MT5 platform? It seems very common for fx brokers to offer mt4, and I would sign up with Oanda, but they don't have MT5.
There are some (as well as many "reviews" in forums). Some of their motivations bear thinking about carefully, though, especially with the ones with account-opening affiliate links. And you might (in general, on review sites and in forums) want to look at contributors' length of history of posting and so on, too: there are famously a lot of one/two-post wonders singing the praises of lightly regulated/unregulated "brokers" many people wouldn't touch. Personally, I know nothing about MT5 but from everything I do know, you're clearly right to want to keep well away from MT4, which is a revolting, ghastly, unreliable, horrible, clunky piece of junk. (Was that enough adjectives to make the point?). Shame about Oanda.
You are too underestimating this big and beautiful robbery made of high-leveraged CFDs. Extremely caution should be executed, considering top regulations, top positive and constructive reviews and of course any sign that your choice provides liquidity or managed to attract pro or institutional traders. Retail independent traders are easy fish, working with pro and firms requires much more efforts but quite rewarding as well. If your broker accepted this challenge then you have nothing to worry about.