As it doesn't have a source of hardware entropy, and the Raspberry Pi actually does (bcm2708-rng/bcm2835-rng), I'd say it's clearly worse from one perspective.
From another perspective, the network on the Pi's connected via USB so it's not particularly great but it ought to be just fine for Tor. (Never actually tried an Onion Pi setup myself, but I have a few lying around, so I might do.)
From another perspective, the network on the Pi's connected via USB so it's not particularly great but it ought to be just fine for Tor. (Never actually tried an Onion Pi setup myself, but I have a few lying around, so I might do.)