Too many variables
there are too many things going on that affect a person "confirming" or "securing" an upgrade PRIOR to actually checking in. In the first OLCI Thread (Can these be merged??) the majority of folks feel there are a lot of kinks that need to be worked out. Plus you have
- Changing other people's rooms assignments, that affect your room options (taking a room off line for various maintenence or housekeeping issues, etc; people extending stays
- A Diamond checks in prior to you
Each hotel and check in situation is different and you have to be flexible.