I wouldn't expect alot of issues really from either granite or the 'quartz' countertops unless a person left some liquid sitting for a prolonged period (much like the coffee rings that Peter described). However, knowing that granite could be perfectly fine even unsealed and is $15/sq ft cheaper, and is a natural material, is very tempting.
I came across what seems to be one of the few unbiased reports on granite counters. After reading through to the end, it seems i would have to convince the granite supplier to give me a chunk of the selected material for testing before i would make a decision.
http://www.forresidentialpros.com/article/10348240/a-look-at-the-most-common-myths-about-graniteAfter all, i do love chemistry...
Incidentally, we are looking at the Caesarstone Atlantic Salt as our leading choice at the moment, unless we go with granite.
http://www.caesarstone.ca/en/The-Catalog/Pages/6270%20Atlantic%20Salt.aspx$90-95 /sq ft installed
