Eagle's Nest has two shuttle lines, one for T4 and another for T5. Shuttle tend to alternate but not always. At peak hours, the line for Shuttle can get quite long but I've never waited more than a few minutes for one to arrive. The trip time is about 10 minutes to T5 and 15 minutes to T4. Shuttle bus stop and wait for planes to enter and exit the T6/7, T5/6 and T4/5 alley ways so occasionally, the trip time will stretch over 20 minutes if you end up stopping 3 times for plane movements. Use the T4 shuttle if you plan to visit QF lounge.