I have no experience but in teh first instance...
1:This is teh most important fact - Its what in teh cup that counts...The new coffee tastes great
2:Well, that is an added bonus, if in doubt refer to point 1: Its what in teh cup that counts...The coffee is pouring fine, right amount, looks good, and correct timing etc,
3:Freshness of beans / The Blend / The Roast ..... Personally I do not think it is a big deal... However it is an INDICATOR...yet it is coming out speckled with darker brown spots
You may find that as time goes on, it changes as teh beans age and maybe; "whats in teh cup"goes off a little... Thus it could be a good indicator..
It could be that as it ages and soothes out; "whats in teh cup" gets better ?
I am sure another more experiences CS will have a comment for you.