I was thinking that in sunlight, the UV would help kill microbes better with the clear plastic...maybe not? I don't know whether or not the plastic will pass UV. Or, will UV breakdown the plastic, shortening its service life? Yes, the metal is definitely more durable, but IIRC, more expensive. Metal could be sterilized with heat, plastic would require chemicals...so then there is that aspect also.I think the metal is sturdier, but its really personal preference.