Foam Insulated vs Insulated sides.
Which is the best?
Are either prone to leaks?
Quietness while running?
Arctic does perimeter insulation the best I've seen. But fully foamed is also a very efficient way of doing it. Which is better? I think they both have advantages and disadvantages. There are several options if you think fully foam insulated is better. Personally I would put Arctic's insulation skeam against any fully foamed for a close enough comparison. But most tubs with perimeter style insulation lack, well insulation and there for cost more to operate.
Neither are prone to leaks. Leaks can happen regardless of insulation type. But they are very rare on well made tubs like Arctic and Beach.
Fully foamed will be quieter.