Figured I would add some first-hand experience just in case anyone else comes looking for information. I made an offer on one of their listings and after I clicked submit, the contract language changed to "net to seller". This completely changed the deal for me considering the seller had a mortgage that I already knew about when I ran my own title search. I called the agent and she had no idea what net to seller meant and told me "don't worry about it". Needless to say, I immediately withdrew the offer.
Since then they've been spamming me with texts on other properties, I've requested multiple times for them to stop, but they just keep changing the phone number they text me from. I looked up their US-based office and it's an address to an office that registers businesses in Florida.
So to sum it up, they will spam the heck out of you, they very likely have no US office, and the agents don't really understand real estate. Use them at your own risk...