I believe that if one a person is taking more than 300 photos on a vacation while walking around is being trigger happy.
Does one really see 300 great images during a single day? Really!
300 great images? Probably not. However depending on your subject matter, you may need to take that many to get the quantity of keepers you want. Easily, if the subject isn't static. If I were doing street or nature photography on vacation, I could easily -- and have -- find places I'd take far more than that in a day.
Such a person would need to carry 8+ rolls of 36 exp film in the old days. Wow!
Indeed. I shot much differently in those days. I carefully waited for what I thought was the perfect shot. I held back in anticipation. I lost many shots I wish I'd gotten, too. I'd say the fact that we don't need a raft of film rolls anymore is one of the greatest freedoms to photography we could ever wish for.
I think the A7's are superb for the discerning photographer who wants to travel light.
I completely agree, but it has weaknesses. Battery life being one of them. Worse so if your vacation doesn't return you to a power socket every night.
For me, it's an interesting step away from traditional mirror SLR technology which has much promise. Combined with Canon glass and better performance, it'll be phenomenal. Just like the first DSLRs.