Here is a cheat sheet of sorts, with some practical suggestions on how to know what you are buying in any price range. It also will help you gauge load size and machine size.
Between the two you mentioned I would go with the 4.5 unless you have 4 or more kids. I think that other machine is just way too big for most needs.
I admit I am a sorter because that's the way I get best results.
The very good thing about both your choices is the allergen cycle (allergiene). That's the cycle that guarantees a true hot wash, which is what gets out stains and odors. Sanitary is a marketing term and meaningless. So allergen is the standard.
Q