I replaced a DIR-855L with the DIR-880L (North America) last week. I reused both SSID's and passwords from the old router on the new router. I had the old SSID's hidden on the old router and set them both to "invisible" on this new router as well (confirmed with inSSIDer, everything hidden). I was all set to have to go through every device I have to recreate all the profiles but I didn't need to. Every device whether Windows, Android or IOS connected just fine with the original profiles without intervention at all. I've had it running for a full week now and it's been rock solid.
If it might make a difference, I've set fixed channels on both bands (as I run another wireless router for a separate network next to it so I don't ever have any overlap), plus set the 2.4ghz band to N only and the 5ghz band to a/n/ac only. I haven't tried it any other way otherwise.