They even broke this for me (in a way) because for some inexplicable reason Google blocks text replacement on Mac in their search.

Yes there are workarounds, but I like using the native OS text expansion and it works everywhere except Google.

I'm curious to know if anyone sees better results by using site:reddit.com vs just appending the word reddit to your search. I've felt the results are similar.

Appending the word will occasionally get you blogspam "here's the top X of Y according to reddit". The `site:` query doesn't have that problem.