At the same power level and general availability with OK support, you're looking at the MyriadX/NCS2. Even then I think the Coral beats it on performance. Next step up is the Jetson Nano (10-15 W) which is a lot more beefy, but power hungry. There are also a bunch of chip companies that make accelerators, like the RK3399Pro from Rockchip and some other OEMs from China, but I have no idea how good the docs and availability are if you're not a big partner. The RK3399 has mainline kernel support which is attractive, but again there aren't many reliable board vendors. Khadas make some nice looking SBCs.
I was also faintly surprised to learn that the Paralella still exists! I always wanted one to play with and I thought they discontinued them.
I was also faintly surprised to learn that the Paralella still exists! I always wanted one to play with and I thought they discontinued them.