I choose a Vosonic 8870 over a Hyperdrive UDMA basically in a coin toss. I have no experience using a Hyperdrive for comparison, but believe there are general strengths of each. Hyperdrive UDMA: speed and built-in crashed card recovery. Vosonic 8870: no-tools battery swap, USB charging, records and plays video, and a super nice screen equivalent to Epson, but slower than Hyperdrive.
A speed improvement for the Vosonic is available in new firmware 1.0.0. I tested a full 16GB Sandisk Extreme IV UDMA "45MB/s" CF card, and backup took 24:15.