Yeah, I am aware it requires a propriety memory card.
The PStv is directly on top of the ADSL router and the PS4 is showing ~73% signal. But did you connect one or both devices via LAN?
Both mine are connected via wifi, but I've got a high end router with decent wifi. Standard N150/300 might not work so good. But if you connect the PS TV via LAN, and the PS4 is showing 70%+, then I think it should work ok.