I think there are plenty of people that have both on both forums and both have supported reasons on why they went with one or the other. Your best option is to do research on each other's customer service, results, and overall satisfaction, as for price I wouldn't worry too much about it as they are both rather close in pricing and you only want to do what's best for your car when it comes to tuning.
Personally I went with another company, McNews Automotive, for a custom dyno tune and I am really pleased with everything about the tune. But if I were to purchase a remote tune, like I am soon for my third recently picked up Focus, I can honestly say I would go with FSWERKS as Randy and the team out there have always been stellar and have been active in the Focus game since before the Focus was out and not many tuners can say that. Their tuning is backed up and supported with years of proven performance and their customer service is top notch.
Hope that all helps.