I would say the new Diamond stuff is decent, but nothing special. They have changed a lot in the past few years. The president of Diamond Audio is now involved with Rockford Fosgate, which you are beginning to see in both company's new lines.
Its definitely still decent gear, just not the same as it was in the beginning. Either way, there is definitely a lot worse stuff out there you could run than Diamond. Just my $0.02.
yeah Diamond isnt bad, theyre more obscure of a brand than the big boys but decent, the only thing is the shops around me that carry Diamond, one also carries and pushes Boston heavilly, and the other pushes Hertz/Audison, and both are names id rather walk out the door with, but thats personal preference from a neutral Focal user