Yeah, you'll find several posts on the net that stainless steel blades are inherently noisier than plain carbon steel blades. That's not quite true. Paramount blades and Ultima Matrix blades with an aluminum alloy chassis (blade holder) and stainless steel runners are noisier than traditional blades, but that's primarily because of the chassis. Why am I confident in saying that? Paramount produces blades using the same construction, same chassis, and same runner design ... but with a choice of different materials for the runners (at different price points). I know a couple of skaters with the plain carbon steel runners, and they are also noisy relative to traditional blades. Meanwhile, the Eclipse Aurora is fabricated entirely of 440C stainless steel, but using traditional brazed construction; and they are just as quiet as traditional blades. [I don't know anyone with the Eclipse blades with the separate chassis and runner construction; so I don't know how noisy they are.]
As I've mentioned in my previous review, my assessment is that the Aurora is superior to the Coronation Ace in all respects, with the critical exception of the spin rocker. You should discuss that with your coach. There are other skaters for which the spin rocker is just fine (really a matter of personal preference).
Other skaters have written that they like the feel of plain carbon steel better than stainless steel (just as some audiophiles like the warmth of vinyl LPs over the coldness of CDs). I'm probably not a good enough skater to tell the difference, but again, there are too many variables to isolate the root cause to the difference in materlal per se. Again, with the exception of Paramount, you can't get a direct A-B comparison, because, in general, different models that are comparable are not identical (and that's certainly true of Coronation Ace vs Aurora). Be aware that stainless steel does sharpen differently from plain carbon steel (and even different grades of stainless steel sharpen differently, as is also true of different grades of plain carbon steel) ... and that will affect edge characteristics. Most high-grade hockey skates these days have stainless steel runners; so even if other figure skaters have plain carbon steel blades, your sharpener should know what to do if he sharpens hockey skates as well (one shop in my area handles figure skates exclusively, but I think that's rare).