Your response confuses me, and I'm not sure what you think I'm "dwelling" on. I simply thought it important to point a major, fundamental difference between a construction used to convey hearsay and one to convey an appearance of a quality (or, with verbs, the idea of being "about to do" something. cf. 雨が降りそう(です) vs. 雨が降るそう(です)) that it was not clear you understood given the phrasing of your initial question. It is far, far more complex than some idea of "目のそう" and "耳のそう", and I would suggest not thinking in those terms at all. (i.e. you might hear a friend describe the process of building a computer and think "That seems/sounds difficult." That would be 難しそう (stem), not 難しいそう (plain form). The idea is appearance vs. hearsay, not eyes vs. ears.)
Your follow-up question "Any difference in usage then?" also confuses me. Have I not been explaining precisely what the difference is in my posts? Or are you asking if there's a difference in usage between よう and みたい (I believe that's the only difference I haven't explained thus far.) If that's your question, the nuance between the two is identical, and the only difference is that みたい is more colloquial/spoken style and よう is more formal/written style (not to say it always _must_ be one or the other.)
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Edited to add the following: please don't take offense at this, but this response of yours struck me as very inconsiderate. Please understand that sometimes your questions can be confusing and unclear. I'm not blaming you for this, because you're still at an early stage of your studies. But Toritoribe-san (especially) and me (less frequently, but as often as I can) have been doing our best to give you information that will help you understand key concepts in Japanese, and sometimes your words come off as being frustrated that we're not reading your mind and giving you exactly what you want. When people spend time typing out detailed explanations of grammar points that are vitally connected to the areas you're studying (even if you don't always realize it), they'd like to feel like their input is being read and appreciated, rather than just being told "Yeah, whatever, that's not what I was asking."