I've had Paxum for 7 years, and Cosmo since they launched but i never activated my card. I don't know much about ePayments and can't help with that.
What i can tell you about Cosmo is that is has exactly the same platform and fees and Payoneer. If you ever used that, you'll know what it means. For me personally, i feel the fees are too high, so i only used it where i couldn't use Paxum.
Now for Paxum...while i have been with them for so many years, it's ONLY because there's nothing else i can use that sites use too and it's cheaper than Cosmo/Payoneer/FCP. For the past 6 months it's been unreliable as hell, kept our money hostage for months while printing temporary cards, now we can't even use those properly because the transfer to them doesn't work most of the time, So bottom line, i won't recommend them either, unless you don't have a choice. If your sites pay with Cosmo/ePayments and u wanna try those, go for it.