Having never been able to get on there, I haven't played the course and am not really qualified to offer an opinion on which routing is "best", other than the fact it seems to be a dynamic thing.
Matthew,
While I haven't played the Composite Course, I have played both the West and East course.
I'm also not qualified, but in my opinion, the routing change made for this Presidents Cup was the right one. As Tom mentioned, a lot of matches don't reach the 18th hole, and thus, it was important that the sponsor marquees saw some of the action. This exact point was also mentioned by Matt Kamienski, the Tournament Director, at a dinner I attended some time ago. Unfortunately, 1 West is used as the 17th hole. While this hole is a great opening hole, it is rather bland for a 17th in match play.
As for the best routing for strokeplay events, I prefer that of the Canada Cup in 1959, which incidentally, is still used by the club members, according to John Green, author of Royal Melbourne Golf Club - History of the Courses.
The main problem with this choice is that a two-tee start is not possible, an issue when it comes to hosting Professional Tournaments. The Canada Cup / Member routing uses the following sequence of holes;
1. 1 West, 392m par-4
2. 2 West, 439m par-5 / par-4 for Presidents Cup
3. 1 East, 304m par-4
4. 2 East, 402m par-4
5. 5 West, 161m par-3
6. 6 West, 391m par-4
7. 7 West, 135m par-3
8. 10 West, 285m par-4
9. 11 West, 416m par-4
10. 12 West, 435m par-4 / par-5 for members
11. 17 West, 401m par-4
12. 18 West, 396m par-4
13. 3 West, 324m par4
14. 4 West, 461m par-5
15. 3 East, 350m par-4
16. 4 East, 184, par-3
17. 17 East, 510m par-5
18. 18 East, 395m par-4
I'd only make one change, which they have done for this year's Presidents Cup, as Tom stated. Hole 16 - swap 4 East with 16 East. Both a very good holes. 4 East is a long uphill par-3, while 16 East plays slightly downhill at approximately 167m, beautifully framed by stunning greenside bunkers on all sides.
I'm very excited about the coming week and look forward to attending the event.