For me it is more convenient Classic, since I used to use the client to enter.
Light is slightly reminiscent of Liberty Reserve, and if you convenient web interface - use him
i strongly suggest not to use wm, as they send sms on every transaction or access to your wm profile and also they lock accounts and ask u to send scans.
better use libertyreserve.com instead
if you want to use webmoney-can prefer light. not classic. it's work in any browers
but now all people prefer to use another payment system-libertyreserve. it's more safely
have a good day
lite is good couse faster to use than classic. just create acc on wm, and you can do your transfers.
if you would like to use aplication instead of web browser, you can use classic, but have to activate it by delivered file-key.