I've flown into CGK 6-7 times in the last 2 years. I've never waited more than 2-3 minutes at immigration, helped a lot as I am normally getting off the pointy end of the plane.

Friendliness - no. I've heard lot's of stories about corruption and bribes but never experienced any issues personally. Just be warned that if you are on business you should get a business visa - certainly for EU citizens anyhow. If you don't, you could be leaving yourself open for hassle.

There is a seperate Customs check, which never seems to consist of anything more than x-raying your bags. FWIW, baggage reclaim is normally fast and efficient, and priority tags work!