It took them only a week to schedule my appointment, which was 3 weeks after that, so less than a month from transfer to interview. Look up my case in transfers subforum.
gc_1881 - jimmypark probably wanted to know what was the reason for interview; they transfer some cases without apparent reason (QA), but most are transferred because the papers that IIO in CSC are suspicious, there was something on the record or in the background check which won't be explained by a simple RFE; that's why they ask you to go to interview. Lucky you, you got SJ. It could've been SFO - SFO is a black hole, swallowing applicants' papers, giving nothing back.