You're right
But if I were you, I'd skip even touching your onboard audio chip through S/PDIF and use USB. Anything over 24/96 is basically useless, despite the (very) rare recordings that sound (very) marginally different on 24/192. There has been a lot of discussion over the matter, and the conclusion by several high profile people in the audio world was that the ideal output format was between 24/48 and 24/96, so going beyond that would yield next to no improvements.
SSDs have their use, no doubt, but it's mainly situational. Make no mistakes, SSDs give a huge performance increase in system responsiveness as well as throughput, but that's still at the cost of long term reliability, which isn't acceptable for anything remotely near mission critical machines. Eventually when the NAND chips get smaller, right below the threshold where data integrity will begin to go down right out the window and the 1$/GB barrier is crossed comfortably, then I might consider getting a system drive.
The thing is, we need to be tolerant over different people's takes on improvements that tend to have little to no objective value. Sometimes both worlds need to come into place for a peaceful existence, but then again, my wallet also likes some peace of mind, which isn't the easiest of tasks when I'm around Head-Fi
Let me give you an example. While I have replaced a few cables on my system, they were nowhere near as expensive as some of the things we've seen here, and more importantly the aftermarket cables were purchased not to improve sound quality, but to reduce/fix sound issues that were present with the stock cables. Now, for me, that's a big difference between going all out to get cables costing hundreds or thousands of dollars to gain potentially dubious improvements in sound, and getting above cheap cables that were purchased for the sole purpose of eliminating issues.