Standard & Mobile credit card processing - experiences?

[comicscardsandmore]

Hello everyone!
I'm looking at getting set up for a credit card processing system (both merchant account & mobile) and wanted to know if anyone had any first hand experience with various companies.
I've read reviews on Dharma, Helcium, Flagship Merchants, Flint, Square and others, and making a decision is difficult.
I guess the one possibility that really concerns me is if a credit card processor thinks you are doing "suspicious" transactions and they freeze your account (and funds) while they "investigate". Not only can that crush your cashflow but it really annoys me to be called "a suspected thief".
Since some of them have no contracts, no minimums, and no termination fees, I'm considering getting set up with more than one so that if the one I'm using freezes my account, I (or my employees) could continue taking credit card payments using another processor while I deal with the frozen one.
Please don't even suggest paypal - I will NEVER use them ever again as they have screwed me over for the LAST time.
Thanks!
Aaron