Some first impressions: I got mine, tried comparing with my old version 560s(both powered using Topping DX5 Lite) - there was a difference in slightly stronger bass, less aggressive highs, maybe slightly more detail, but this could be just different tonal balance tricking me. Also tried the fabric pads, felt like bass was more impactful, even though the measurements suggest that it should be reverse. I prefer the velour pads both in comfort and sound(except bass impact, I guess. Seems like velour pads bass is louder, but fabric pads bass is more impactful). But overall I didn't notice much of a difference compared to 560s in sound after A/B testing, which left me a bit disappointed.
However an hour later I've tried to just listen to 490 Pro on it's own and found that I enjoyed the music way more than I usually did on my 560s. Not sure if it's because less aggressive highs allowed me to play music a bit louder, or something else. Hard to judge right now, I wanna listen to them for a week and then do another A/B test against 560s.
In terms of comfort - 490 doesn't have the issue of pressing hard in front of my ears(which 560s does), but the dust filter irritates my ears, baffles how Sennheiser overlooked that. They definitely should fix that in a silent revision. The irritation from dust filter is not that bad, and for me 490 is much more comfortable than 560s. But I am definitely looking to replace the filter with something else, especially since I didn't notice sound change when I removed the filters. Probably will try to use the dust filter from 600 series ear pads.