The RM-VLZ620 succeeded in all aspects of programming which I attempted This included teaching it commands from an ancient remote for an original, still functioning 29 year old RCA (Hitachi) three gun front projection set.
Over the years I had become concerned that if my original remote for the above ever failed (as they were unavailable) from hard use by two boys I would be SOL. Any learning remote I researched was way too expensive hence I did nothing until I checked once more and the Sony RM-VL700S was available for a very reasonable price. I easily taught the RCA remote to it and ten years later was able to do so as easily with the RM-VLZ620.
I also tested code entry on a Sharp LC52E77UN and a Yamaha YAZ71 sound bar. Both worked perfectly and the feature where the remote controls the audio component volume in lieu of the TV did also.
I actually purchased this (Amazon) for my age 86 mother-in-law for a Sharp LC46E810UN, a Sony HT-CT350 sound bar, Sony DVD/VCR and Scientific Atlanta 8300 DVR cable box. The after market remote the cable company provided was completely unintuitive and did not control the Sony Sound Bar volume. The TV has NetFlix built in and that of course required the Sharp remote. Having to use the Sony SLVD360P remote completely ticked everyone off!!!
I plan to set up all the above this weekend and will report back......