My subjective opinion - back in the day (80's , 90's) I saw those badges and respected them and coveted them (as a teenager they were out of reach) hell I visited Steve Dinan with my Dad back in the mid 80's for a chip intall on my dads 1985 528E. When in my 20's I could afford to buy a used E30 M3 I bought many Dinan parts - but never hit the points total for a badge (I sold that car for a Bronco
)
That said now I think if you have a vintage BMW they are cool - but anything after the 80's/90's might be a pass just my IMHO. I think now that Dinan is a small part of the Holley machine a little bit of the sparkle has faded
ps- Love my Dinan springs and bumpstops on my M340 - so still a fan just not feeling the specialness