Does anyone know of a usage difference between these two if any? Like 見る vs 観る and 聞く vs 聴く have clear usage differences. How about these two? Prior to studying recommend here, I had never seen 勧め but commonly saw 薦め when used by restaurants. So I’m thinking that one might be for food or things.
I’m pretty sure I’ve mostly only seen おすすめ…
お勧め has the nuance of “I recommend this thing because it’s what I do and we can do it together”
A related kanji compound would be 勧誘
お薦め has the nuance of “I recommend this as a good option to choose”
A related kanji compound would be 推薦.
So you can see why it would be a little odd for a restaurant to use お勧め, but your friend could use it to recommend making some kind of food. (If they really like to use kanji).
Source and more info
And yeah, おすすめ and おススメ are probably the most common in my experience, at least if you’re sending messages casually.
Got it. Thanks.