A SSD equipped Zotac ci327 will definitely be faster than the C2
The Intel Celeron® Processor N3450 comes with integrated
Intel HD Graphics 500 (click)
Intel HD Graphics 500 is based on Intel's Skylake architecture, so whatever that can do the N3450 will be able to do.
Intel Skylake cannot fully Hardware decode 10bit HEVC content, that comes with the following Intel Kaby Lake Architecture.
There is Hybrid GPU / Software decoding of 10bit with Intel HD Graphics 500. I believe hybrid works in Windows only.
Problems will be encountered with 10bit 4K HEVC decoding as the N2450 will have to use Hybrid / CPU Software only decoding and will likely run out of grunt.
You should be fine with 10bit 1080p only, Hybrid / Software decoding on a Quad Core Intel N3450 that can ramp up to 2.2GHz.
The Box better have good cooling if turbo boosting up to 2.2GHz for 10bit HEVC Software decoding.
The ODROID C2 will Hardware decode nearly anything you throw at it,
except Youtube 4K VP9 content.