Upgrade to Scott Nixon usbtd dac

I've been living with my Scott Nixon dac w/ upgraded power supply but lately I've been wondering. It seems everyone is talking about asynchronous dacs of different varieties to help squash jitter. I like NOS dacs but I can be sold on other options, I'm not into hi rez files I just want to get the most out of my cd playback through my computer. I've been looking at the Wavelength Proton but now the Schiit Gungnir has caught my eye. Are there other dacs around $1K I should be looking at?
I'm guessing by the response to my question that either
1) There isn't anything that is better for $1K than my Scott Nixon dac.
2) Everything is better than my Scott Nixon dac and that I should know that.
3) Or that it's a big secret and that the only way to know is buy and try then discard those that don't make the cut.