I bought mine used already updated to 217II D which is the upsampling option to 24/96. I can't comment on what the sound differences are as I did not have the regular 217II to compare to the 217IID. A friend of mine had the 217II and it sounded fantastic so not sure if the upsampling option is really worth it.
These are older DAC's and I don't think you can find them often used anymore so you probably do not have the option of finding a used 217IID too easily.
The software update from the 217 to the 218 software was worth it in my opinion. I don't recall the cost as I had it done about 10 years ago. I'm not sure if the upgrade is still available. I would contact Silversmith audio and inquire about any updates if they are even still available for the 217II. These DAC's were made around 2000 and were discontinued around 2004 but Silversmith audio would be the only retailer who could provide details.
