The Hub75 boards are great, but aren't really comparable to the ulx3s as they have extremely limited I/O options (a whole ton of output-only TTL level shifters, + 2 gigabit interfaces). Great if your project fits into those constraints, but few projects do. Plus they are only available with 25F size parts whereas the ulx3s is available with a 85F part.
Comments
The Hub75 boards are great, but aren't really comparable to the ulx3s as they have extremely limited I/O options (a whole ton of output-only TTL level shifters, + 2 gigabit interfaces). Great if your project fits into those constraints, but few projects do. Plus they are only available with 25F size parts whereas the ulx3s is available with a 85F part.