Absolutely look for a strong cable jacket that will withstand bends, chemicals, and UV exposure without weakening sharply.
Look for an integrated circuit breaker or surge protector.
Metal frames may conduct heat faster, yet they are stronger and dissipate heat faster for a reduced chance of catastrophic failure, especially when properly grounded. Plastic frames will warp; thin plastic frames will develop localized hot spots.
Depending on your application, consider looking for switch covers, well-separated outlets, and bright-colored cabling.
Recommendation: Tripp Lite Isobar
Highly durable power strip with metal frame, integrated surge protector, overheat detection, and isolated outlet filters. Lasts decades while protecting against over-current risks such as fires and meltdowns.