I have a question regarding the standard 8 cube modular ice makers. When looking at all of the "models" and makers of these ice makers, prices and model numbers vary greatly. And yet to me they all appear to be the exact same unit, made by Whirlpool, or some manufacturer making them for Whirlpool. Are they all identical and just rebadged with different model numbers? Can I buy any one and use it or are there real differences between them? IF so, how many basic types are there out there? Thanks.