I’ve been using the Side by Side series for some time now.
It seems many of my Adult students prefer Side by Side over Interchange (Cambridge Press). Don’t get me wrong, both Side by Side and Interchange have their positive points and both are very good for self study. It’s just that in Japan, Side by Side is well known and very popular with new ESL students .
Interchange? Well, it just never really took off and that’s to bad.