I don't really use hydro tabs. It's England, it's not hot enough to need electrolyte replacement.
Depends how sweaty you are. I used them otherwise I end up needing a piss stop every 30 minutes. With the hydro tabs I can go for hours without needing one.
I presume you're inferring the salt content is allowing you to retain more fluid?
If you're drinking water and pissing too much, you're probably drinking too much.
You can get salt from sources other than hydro tabs - cheaper and/or tastier.
Torq for gels and bars.
I don't really use hydro tabs. It's England, it's not hot enough to need electrolyte replacement.