We are in production with N/D 10.0.1 and Xpages applications and boy, it has been a struggle. Designer is more crippled after the HCL takeover than it has been before and event handling in the old JSF stack changed for whatever reason making it necessary to fix XPages apps that have been running with no changes for 5 years since 9.0.
A lot of our customers used and use XPages to modernize their Notes apps and shift their notes developers from LotusScript to JavaScript/HTML/Java - a more web compliant stack. I hope that HCL will be able to come up with a roadmap for XPages or they will lose a significant amount of loyal customers in the app space. Currently, all we see in the Node/domino-db arena is not feasable for a company that invested into XPages/Domino so far - it is a rip-and-replace and with that, most customers I talk to will then pull the plug on Domino as well. IMHO, HCL underestimates the reach that XPages have in the Domino App arena.