For the price (20 + 7 Porto I paid) it is really great!
What strikes me positively:
+ Good cushioning
. + Spacious main compartment including notebook compartment (or for a padlock;)
+ Smaller pockets for money, pens, knives etc.
+ Lightweight aluminum bar (on request to be removed)
+ Very good workmanship
As a neutral I rate:
o no chest strap (but missing only on the bike)
o no rain cover
Until now, I notice anything negative, but it'll resent, if necessary.
CONCLUSION:
Since the neutral point (for me) have little impact (because they were retrofitted if required) and I do not think to find a better backpack for that price, I forgive 5 Stars.