Could someone please enlighten me as to the advantages and disadvantages to these two methods of updating my phone. In particular I would like to know:
i) Will updating with either of them un-root my phone? (I am running rooted stock KE7)
ii) Will either of them wipe my phone, or do I keep all my apps and stuff?
iii) Any big advantages of one over the other.
Kies is the officially supported way of updating your phone ROM. Odin is leaked software and not supported.
1. Depends on the ROM you flash. Official images will unroot your phone, custom ones might include root and hence will not unroot.
2. Again it depends on the ROM you flash. Flashing a CSC will wipe everything. Rule of thumb; Always do a backup before flashing anything.
3. Kies is known to badword things up. Odin works flawlessly as long as you follow instructions for the ROM or know what you are doing.