Well if the 655 is still working, keep it. If it ain't broke don't fix it. It's been one of D-Link's best routers for a very long time.
Personally I use the DIR-890L at home and has been running strong for over a year for me. I do have a 4K TV streaming daily without issues. I do not have much experience with the newer generation routers (DIR-869, 878, 879, 822, 882) or the COVR systems in real-life day to day usage unfortunately.
Hopefully some other users can give their input and experiences.