Elgato Cam Link 4k HDMI Camera Conn.

Ironically, there may be more cons than there are pros with regards to the Camlink 4K, but what it does, it does so extremely well, with real consistency and reliability.

If you're reading this then you probably already know where the card shines and where it does not, so here's my recommendation:
1) If you're a 4K Pro, then go for one of the PCIe cards in the Magewell lineup.
2) If you're just starting out on 4K or want excellent HD capture capabilities, then this is the card to buy.
3) If you're working with 720p only, you will probably be better off getting one of those cheap Chinese USB2 knock-offs and save ~80% of the Camlink's price as well as ~90% of the required bandwidth.