Problem is, for every benefit there is a downside and some of the benefits aren't that interesting to me.
Benefits seem to be:
1. Alignment without mixing (which is bad in some languages). I don't align.
2. Code looks the same for everyone. Doesn't need some workarounds if you publish code or present it outside the editor to get your prefered width.
Downside is:
1. I use variable width for some filetypes. People might not agree with that. I wanted to convert all my tabs to 4 spaces when I realized that I've set sass to 2 and sometimes change it to 4. Conversion is possible, but tricky especially if you align.
2. OCD/Perfection clashes. Tabs kind of make sense for indentation.
The problems I have with tabs are:
1. Barely anyone seems to use them anymore.
2. Some languages I like (like YAML) don't allow tabs.
3. Needs some non-standard CSS to get them to display as 4 Spaces in the Browser instead of the overly wide 8. I think GitHub converts them automatically to spaces in the preview to avoid that issue (though your still at 8 then).
I guess I might end up with spaces in the near future. It's kind of a "What I like" vs. "What others use" situation. I don't think there is anything wrong with tabs unless you really have to align your code.