It sounds fine, like a guitar recorded in a booth!
It's very hard to create a small vocal booth that won't have some low end resonance, you could try adding traps, etc, or just work out the frequency and cut a bit of it in mixdown. Generally, you'll find something in the 400hz area that needs to be cut a bit.
Personally, I prefer record out in a larger room, using some packing blankets to kill reflections, if necessary. This allows the bass room to dissipate, and reduces resonances. I realize it isn't always possible to work that way, though.
I think your recording sounds fine, and would be pretty easy to mix.