My understanding is that as far as sound quality, the only distinguishing factor between a DAC-1 and DAC-2 is better capacitors. W4S will upgrade my DAC-1 to the same capacitors are in the DAC-2. I was also thinking that if it's going into the shop, I could do the Femto clock upgrade. All this is $300. I really like my DAC-1 and admittedly I have virtually no experience with standalone dacs. I think my system is fairly resolving- is this a decent "investment" and I use the word investment loosely as I don't think any audio gear really is an investment. I bought my DAC-1 second hand and really don't have a ton in it already.
I would love to hear from anyone who might have done dither or both updates.
Just one person's opinion: upgrades don't really hold their value in the used market. If that's a consideration, and you're looking for a better DAC, selling the DAC-1 and buying something better may make more sense.
Anyone notice that the Femto clock upgrade alone now is $275? When I sent my Dac1 in, the clock upgrade was $150 and the capacitor upgrade was $150, for a $300 total plus shipping. Holy cow, glad I got in under the wire.