As for the benefits that come from the GiroPay usage, the main one is its speed and security. All transactions are safe, no additional data except registration details are required, and your money will not be stolen or intercepted by a man-in-the-middle.
The second point is that GiroPay does not ask any fees either for depositing during the gambling process, which means if you are ready to play for real money, you bet exactly the same sum you want to bet. The third point for GiroPay is the fact that all you need to process the payment is just to login to your GiroPay account and choose a preferable bank or service you would like to pay to, and then, after choosing the credit card in use, other processes are performed automatically with no additional steps required.
As for drawbacks, GiroPay is not perfect at all sides, yet, close enough to it. The first flaw is obvious within its core: GiroPay is available only within Germany and is designed for Germans. Thus, it cannot be used by people within other countries, as well as it cannot be used within the United States. The second major flaw is the fact that the GiroPay service cannot be used for withdrawing, which means that if you would like to take your cash winnings, it will be required to use another payment service for this.
To sum everything up, GiroPay is a good service that is accepted at most part of online casinos nowadays. The main plus of the GiroPay system is the fact that if you are from Germany, it can be used almost in any way for both online casinos and any other e-commerce without any borders or difficulties, as well as GiroPay is fast and simple, having an intuitive user-friendly interface. Moreover, you can always check whether your bank supports this system or not right from its website before going further.
Its weak sides, however, are also major, since if you are not from Germany, it will be required to check any other method. And it is sad that there is no option for withdrawing payments through the system: the more systems are at place, the harder are the terms of usage.