Hmmm. I don't think that the problem arises with the purists really. Rise Up Singing (RUS) is a fun book. We have three copies at home and use it a lot.

The problem I see with RUS is that it has become a de facto standard with the versions and songs being set in concrete.

Some singers will actually glare at you should you dare sing a song that is not in their bible.

An even worse situation arises if the song is in RUS but it is not the version that you sing.
In that case your 'beautiful rendition' is marred by the rest of the crowd singing a different version which is both discordant and embarrassing.

I suppose though, that it will come to pass, and I'll probably buy a few copies and enjopy it.

Should we call it the new testament? :-)

Bert.