Yeah, good call as regards different lines. With Geoffs some claim their precision line is the same as the BLS ones. While their super precision is from a different producer. Also there can be drought of particular weights of BBs. Then suddenly three or four different brands get a restock. Wouldn't be too conspiracy like to imagine quite a few of them come from the same source.
The food comparison is a good one. No point upgrading your primary to a high extent only to plug in a weedy lipo and run it with a poor match of BB.
Excellent, that was the thread I was thinking of. Find AATV to be thoroughly entertaining lads, who are good to reply to comments and interact. Used their non bio video to select a few brands to test. Still your experience would certainly give me a degree of hesitancy in trying 6mm.
One of the shortcomings is even if you find a good BB, it might not necessarily be in stock year round.