Alright, after having been a couple of months very active on PIWI247 and having used them in the past already aswell, I think I have a good picture of them and it is time to share my experience.

I made my deposit via BTC, the money arrived in time. After having made myself familiar with their software, the grind started.
The fact that you have Pinnacle with double limits + an option to use Betfair exchange within one tool is a huge factor to me.
It allows you to shift the money between Pinnacle and Betfair exchange within seconds, depending where you get the better price.
Their customer support is 24/7 and throughout the past month, I felt entirely safe having my money with them.

After having run really well and having made a pofit of around 20.000€, I wanted to withdraw my money yesterday.
Within 24 hours, the money was in my Bitcoin wallet.

If you are looking for the imho optimal betting solution, Piwi247 is the answer.
Double Pinnacle limits + 10.000€ exposure limit Betfair exchange option within one account, good customer support, fast payment even if you win big.

Small suggestion for improvement (I have already informed them via Chat); Recquire 2FA to even increase the security.
But overall highly recommend giving them a shot if you are looking for surely one of the best tools out there.