The current technical maturity classification is not really apt.
Consider this - Some known issues & Many known issues.
They do not imply that the "Some known issues" beta is stable or more matured. Literally, it just says that as of now, there are only some known issues. It relates to the after effect of the maturity, does not directly talk of the maturity.
And for "Many known issues", its just another beta for which many issues have been reported. Gives a feeling that the users have found many issues.
Instead, something which actually talks of the maturity would be a better approach. So, something like a rating of the maturity on the scale of 1 to 5, or a classification like - "Stable", "Highly unstable" (Maps 3) and something for the "Still needs a little ironing" section.
Hope i was able to convey my opinion, do share your thoughts too.