What's the difference between foam coated and foam filled in terms of comfort etc? I can't find a comparison between these two and it is something I'd like to know in order to choose between 2 strollers. The Joie Mytrax Flex is one of them.
I wrote a full article about different stroller wheels type and their comparison/differences here. Read it to know more details, but basically, the EVA foam is the simplest and "hardest", "most prone to wear. The advantage of those is mainly their lower price as well as lowest weight (with no threat of punctures). The foam-filled tires, on the other hand, are much closer to air-filled (inflatable) tyres - so usually larger, more all-terrain, adding a bit of natural suspension - while (as opposed to air-filled wheels) no punctures there as well. These are, on the other hand, more expensive as well as bulkier, heavier - so they make the pushchair heavier and bulkier overall.
If just the city is your playground, I would go for the lighter stroller wheels, most of the time, and for more bumps and holes, I would opt for the more all-terrain option. But this all depends on your personal preference, driving style, expectation, and budget as well.