I have read the reviews on truspilot, all the good feedback looks really fake, the bad feedback look like cryers that at the end cry for a problem of 10 euros, like always on the net.
So let me give you a short feedback ( i cannot a long one without being accused being part of Ipaytotal )
I have 2 set up ( 2 UK companies ), i paid for one 500 usd fee, for the second they accepted me but with 900 usd fee.
They got a bad customer service, so or they are really or they are not enough in the company, but i don't care about those things. My interest is the money and they pay , it s what count for me.
Their adress is a virtual one because i use this address too, so i m not sure they are British, and i m not sure you will find them if they run with your money.
Now, i have a way to think , it s a personal one : for banks there is rules, for Processor there is also. If you know the rules, and respect them then it should be fine.
So go for it or no, at least my feedback is from a real user of their services.
PS : there is a post on this forum about smartcard payment, don't know them or don't use them, but there is few good feedback, maybe you should have a look.