This topic keeps getting brought up recently. I think Reef Crystals changing their formula prompted it. Run a search and you'll hear recent complaints about R.Crystals. Personally, i tried it once and didn't like it, but that's just my preference.
You're going to get lots of different opinions on salt mixes, but they all seem to do a good job.
I use Red Sea Coral Pro, myself, after switching from Red Sea salt. I think it's great salt but I won't bash any other salt out there.
as for the Get Tanked salt, I have no experience with this.