Hi fbushaw,
We replaced the L610 with the L620 and the L612 with the L622. These new meters are pretty much identical in terms of hardware and the case enclosure, however, Wagner enlisted the help of OSU and Mike Milota by having a study performed on the higher range of dense wood, specifically in the range of about 0.60 to 1.00. The original study we did did not reach into the upper s.g. regions, and reports suggested we could improve our accuracy in these upper regions by performing the study. From the results, I incorporated a new algorithm into the meters' firmware which took into account the new information. The results confirmed and still agreed with our original results where the s.g. overlapped, but also gave us in new data in the higher s.g. regions.
I don't think you need to worry about replacing what you have, but when you think the time is right, we now have an even better solution. We are always looking for ways to not only come up with new solutions, but to improve on the solutions we already have whenever possible.
Regards,
Tim