Spoiler

> Book casting does not train mana any more than any other method
> of using your power.

I have no code dived info on the subject, but my personal exp. says that using PP's in larger chunks trains the Ma stat faster than smaller chunks. If using the Phial trains the Ma stat, I suppose I have just been very unlucky with my attempts.

> Out of curiosity, how many of you use bookcasting as opposed to

Bookcasting is not supposed to be 'opposed to' but rather as a 'compliment to' regular casting. Here is an example of using bookcasting that I would use in my limited turns games: read your starting books once, bookcast the most PP's expensive spell you can, take a few steps through the wilderness, cast again, a few more steps and so on, when you get to the SMC you will be quite likely to gain an increase to your Ma stat upon gaining exp. level 2. Very efficient : ) If one is not concerned about turns, they could then exit the SMC, wilderness bookcast a bit more, and gain another increase to Ma upon gaining exp. level 3, and so on for very easy and impressive gains.

One other use for bookcasting, is to allow a more flexible early game. Personally, I have beat the game a gazillion times and care little for the Terinyo stuff with wizards, they just don't need it. I like to head west to the BUGWIL for an easy ~13 exp. levels. If one uses this tactic without making use of bookcasting, they will not have enough spells to last them through the early game. Of course one COULD scum the ID for more offensive books, but that's not exactly fun.

There is also the facet about not wanting your survival to be so dependant upon the RNG giving you books. I have had games in the past where offensive spellbooks just didn't come along before Dwarftown, and yes that was with TH (as I used to be a believer). If a player is crafty with avoiding traps, and gets the waterproof blanket from the SMC, your books will stay safe in your inventory. Basically, just don't kick a door without first dropping your entire inventory by using the ':d +' command (which coincidentally looks like an emoticon that lost a tooth : )), get higher piety as soon as possible for the 'luck' intrinsics, and don't take books into areas you know are highly trapped.

One other use, is to help save your elemental spells for later. Not all spellbooks are created equal, some have internal counters of only 1, that means you may only get one reading of, say, frost bolt before it disappears. You would like to use it against the fire monsters you encounter, but you also want to save it for the monsters in ToEF. Bookcasting it will let you do both. Yes, you may find another random spellbook of frost bolt before you want to do the tower, but that's far from guaranteed. You could do the Rift before the tower, but there are some tough monsters in there that may kill you at a low exp. level. You can also complete the druid quest for one, but you might also kill an out-of-sight cat in there, and that is an extrememly frustrating experience, believe me! : ) Bookcasting keeps you from feeling compelled to go on quests you may not like (I don't).

Another use for bookcasting, is for killing monsters that 'shrugs off bolts'. Specifically Kherab. It is very frustrating to eat up all of your castings of everything trying to kill this guy, and still not get the job done, yeah I've done that too : ). With bookcasting though, you can blast him a bit, teleport to the wilderness, blast, TP, and so on until the job is done. When he's finally dead, you will have ALL of your spellcastings left, and a larger Ma stat for your trouble : )

So bookcasting might be for you if any of the following applies:
You don't like scumming the ID for books.
You don't like doing side quests like druid, or Rift, just for books.
You like having the option of a quick start in the BUGWIL.
You like having many near effortless increases to your Ma stat.
You like being able to control the rate at which your spellcastings deplete.
You like being able to kill monsters that 'shrugs off bolts' without having to worry.