We have recently launched a subpage dealing with peptide separation;
www.sequant.com/peptides
The potential of using HILIC for peptide mapping is illustrated with three trypsin digested proteins, BSA, Cytochrome C, and Ovalbumin, along with identified sequences and experimental conditions. There are also 20+ references to peer reviewed papers with useful information.
Our experience indicates that one can expect a higher sequence coverage when combining HILIC with classical approaches, like reversed phase.
An additional feature when switching to HILIC, or combining it with a reversed phase strategy, is that hydrophobic peptides not detected with a RP column can be identified. HILIC eluents typically contain a high percentage of organic solvent hydrophobic peptides are potentially less prone to precipitation during sample handling on the column than in RP chromatography.
Another feature using HILIC is that higher sensitivity can be expected for many peptide sequences, due to the high percentage organic content in the mobile phase which enhances volatilisation in the detector.
In terms of finding information about retention prediction in HILIC, I can only relate to our phases, and they are predictable.
We have a free on-line retention prediction tool for HILIC separation.
www.sequant.com/prediction.
This tool was developed for small molecules, and we have not yet adapted it for peptides...but in the reference list you will find review papers worth reading and two studies which could give you some input on how to predict retention for peptides in HILIC mode.
. Depends on the application. Analyte size, hydrophobicity, etc will dictate optimal RP column. 