What I'd like to see in a rules compendium of 160 page length?
Complete removal of "fluff". In order to use this book at the table as a rules reference!
No reiteration of DMG information.
Ability Scores: 2 pages.
Races: 10 pages (20 races): Aasimaar, Changeling, Dwarf, Elf, Gnome, Goblin, Halfling, Half-Elf, Half-Orc, Hobgoblin, Human, Kalashtar, Kobold, Lizardfolk, Orc, Shifter, Teifling, Warforged. +2 more (Drow? genesai?)
Classes: 40 pages (20 classes): Barbarian, Bard, Beguiler, Cleric, Dread Necromancer, Druid, Favoured Soul, Fighter, Hexblade, Monk, Paladin, Psion, Psychic Warrior, Ranger, Rogue, Sorcerer, Warlock, Wizard +2 more (ShadowMage from ToM?)
Equipment: 8 pages
Feats: 40 pages
Prestige Classes: 20 pages (10 nonDMG PrC's )
10 pages Domain/Spell/Invocation/Power lists per class, listing which book contains the spell.
No Spells instead an indexed reference sheet containing all the spells from PHB, SC, CM, CArc, etc. After the arrival of the Spell Compendium, I see no need for yet a further reference book containing spells.
No Monsters (indexed reference sheet)
130 pages not counting the indexed reference sheets, which I would prefer to be removable for lamination. I guess I have room for more feats, classes & races.
Of course, if there were a Feat Compendium on the horizon, I'd gladly dump the feats, and go for more Equipment, classes and races.
Dammit. Forgot Skills. Need skills.