THANKS to JED I came across this great extension.
First of all:
The module simply looks great, and perfectly integrates into any site, with a wide range of backend customization options.
GREAT support from Balint. There were some customization issues, and I opened a ticket on the developers' site, and was helped within hours only. It can not be any better.
Nice features, like Captcha integration, password strength indicator shown when registering, to name only two.
TO SUM IT UP:
Definitely worth the money, and saved me a lot of stress and time compared to other - often premature - software.