Pros
Both managers are extremely understanding and do not demand you stretch yourself or do work you cannot reasonably do or learn; in addition, they're quite flexible with hours provided you're productive while you're there. Excellent entry level summer job, they're willing to teach you the basic skills and let you get faster/work out more yourself.
Kontras
Inconsistent hours; if you're looking for a consistent 8 hours a day 5 days a week, it's entirely normal to have the odd day or two off when you're not needed because of a bottleneck somewhere down the line.