I'm a regular customer of Nissan SC in Chan Sow Lin since March 2011, so far so good, no complain at all for me. Can book service time from Nissan hotline, estimated finish time always meet their promise, quite friendly, already got 3 items replaced/fixed for free under warranty without any hassle at all, and recently they've improved their procedure of receiving customer so that it's faster.
So conclusion: still satisfied with their service.