I'm not sure about losing speed, that depends on a lot of things, not just using a VPNWell you dont need one for the reasons a lot of us do and thats our IPTV provider has been block buy our internet provider.
There are other reasons, big one is not allowing your ISP to see what your up to weather that be downloads viewing IPTV both probably illegal.
You actually loose speed when you use a VPN but it will still be more than enough in most cases to hide what your upto.
I see absolutely no difference in speed with VPN on or off,
I put that down to my router being easily able to handle the VPN routing at the speeds I get .
So with the right hardware and VPN settings, you won't see any loss of speed necessarily