L-Arabinose Effects on Growth
I have reason to believe that L-Arabinose, used to induce lambda red in pKD46, may inhibit the growth of our standard lab strains.
Test: grow wt and r-m+ in varying concentrations of L-Arabinose and monitor growth as OD600
Use the shaker-incubator-spectrometer
Plate pattern

Legend translation
"Series 1": 0 L-Arabinose
"Series 2": 1 mM L-Arabinose
"Series 3": 2 mM L-Arabinose
"Series 4": 5 mM L-Arabinose
"Series 5": 10 mM L-Arabinose
"Series 6": 20 mM L-Arabinose

The level of L-Arabinose I've traditionally used to induce lambda red (20 mM) clearly inhibits growth in the r-m+ background.
Growth yield is decreased by 20 mM L-Arabinose in both strains
Ampicillin, used to hold pKD46, clearly exacerbates the effects of L-Arabinose in the r-m+ background
Follow-up: I tried 5 mM L-Arabinose as inducer in experiments on effects of host restriction (o86), and it seemed to work as well as I would have expected with 20 mM. Note, however, that I did not try the latter control, so the conclusion is strictly subjective.