I like world of "Blame!" but this collection is hard to be simply scored, 'cause stories are too different.
* 'Netsphere Engineer' and 'BLAME!²' are canonical parts of 'Blame!' story. 10/10
* Kozutsumi (Parcel) - very cool story in the style of 'Blame!'. 8/10
* 'Zeb-noid' and 'Senshi Kouchuu Suzumega (Winged Armor Suzumega)' - nice sketches about endless battles in far space 5/10
* 'Pump' and 'Numa no Kami' - they look like dark horrors and are stylish, but they are a bit pointless and cannot really scare anyone. 2/10
* All 'Blame Gakuen!' parts are school parodies with characters from the main story. I didn't find them funny and feel like "WTF I was just reading!?" 1/10
So stories in collection are really from 1 to 10 =) And rounded average is just 5 (precisely - 4.5)