As one can easily see from the many results, the quad-core 1.4GHz ODROID-X can easily outperform the dual-core 1.2GHz PandaBoard ES. The ODROID-X is priced even lower than the PandaBoard ES ($129 vs. ~$160 USD). The only problem with the ODROID-X is that it's still shipping in limited quantities and out of Korea compared to the PandaBoard ES that is available from multiple Internet retailers within the United States. The ODROID-X also has yet to be as widely supported by different Linux distributions as the very common PandaBoard / PandaBoard ES. Regardless, the ODROID-X is one very compelling ARM development board with rather nice performance. If the open-source Lima driver project can mature quickly for supporting the Mali-400 graphics, this could become one popular development board with Linux hardware enthusiasts. The next quad-core Exynos 4412 benchmarks coming up on Phoronix are comparing the ARM Gentoo Linux performance to Linaro.
You can compare your system's performance to these ARM results (regardless of OS or system architecture) with the open-source Phoronix Test Suite by running phoronix-test-suite benchmark 1208244-RA-ODROIDX6992 to facilitate a fully-automated and reproducible side-by-side comparison.