Good little water heater
Your review: Good little water heaters. Small size, and good design reduces chance of corrosion,(plastic tank). Not recommended for high pressures (above 100 psi) because of the chance of leaking (plastic tank). But under normal service I've seen these things last over 10 years numerous times.
Pros: No relief valve required. No corrosion issues due to plastic inner tank.
Cons: Not reliable under higher water pressures (over 100 psi) because of the plastic inner tank.