Worth doing upgrades to my W4S DAC-1?

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.