I did a light benchmark of their 512MB VPS[1] which is insanely cheap. The only things that change when moving to the 2GB VPS is RAM, hard drive space and total data transfer. The CPU remains a single core and the same speed according to [2]. It's possible there's less contention but you'd need to find a benchmark for the 2GB VPS to know for sure.

If you're after any specific benchmarks give me a yell and I'll see if I can provide one for you.

[1]: http://smerity.com/articles/2012/hetzner.html

[2]: http://wiki.hetzner.de/index.php/VServer/en#Which_clock_spee...

Edit: Came across a review of VQ19 (2GB VPS) vs EQ4 @ http://code.google.com/p/catz/wiki/DedicatedOrVPS