So, I have played my first 15 Blackbox games, so it's time for a first assessment.
I love [ B ] because I get games fast, I don't know what team I will play and it's just plain fun.
I hate [ B ] because I always play against the same races and BBR seems to do the exact opposite of what I thought it was intended to do.
Let's have a look: (Yeah, the sample rate is far too small to give any indication on statistics, I know ;) )

8 games with High Elfs:
3 Ogres
3 Orcs
1 Undead
1 Chaos
Playing against Ogres really gets boring and always having 3 players mng or dead is frustrating, especially as the next 'recovery' game will be against Ogres or Orcs anyway...

7 games with Undead:
2 Chaos
2 Skaven
1 Dark Elf
1 Ogre
1 Orc
So the bashier Undeads get the softer games, strange... Can't I get a Skaven team for my High Elfs, please? ;)

Overall Record: 5/2/8
Ouch! I thought I'd be better than that, never figured myself as a picker in [R]. But obviously I must have been picky as my [R] record is far better than that...

Conclusion: Too many Orcs and Ogres, interestingly no Dwarfs or Khemri yet.
A recovery game vs a softer team, just once in awhile (every 3rd or 4th game?) would be really nice...
Oh, and I think I will stick to [ B ] anyway, not really interested in [R] anymore.