The favored soul

[Thurbane]

IMHO, the Spell Compendium is great for casters who know a limited number of spells (Sorcerer, Wizard, Favored Soul etc.) but can be a bit unbalancing for casters who have automatic access to all spells on their list (Clerics and Druids, primarily).

The best house rule I've enountered so far is that if such a character wants a new spell from the SC, he swaps out of of his existing PHB spells of the same level to take it, similarly to a Bard or Sorcerer swapping out one of their "spells known".

 

[Nifft]

Cats Grace.

Not a Cleric spell.

Cheers, -- N

 

[Trouvere]

The Divine Crusader in Complete Divine does the only domain spells access.

True, true. Or at least, it gets access to the spells from one domain only. But that's definitely flavourful: "the Divine Crusader serves as a symbol of a specific aspect of his deity's portfolio." Unfortunately, as a straight cleric or favored soul, you can't become a Divine Crusader until 11th level, due to the BAB +7 requirement, and why would you want to? It's really intended as a Paladin PrC, trading BAB for spell advancement, no? Or I suppose for a non-spellcaster who suddenly gets religion.
Of course, there's also the crazy Sovereign Speaker from Faiths of Eberron which ends up with 11 domains.

 

[evermind]

the Favoured Soul is pretty balanced as is, if oddly unmitigated in flavour 8well, it is from the MHB originally, so what do we expect ?). Had some in campaigns herebabouts, up to level 14, and they never seemed overshadowing or to "wuss out". Very reliable class, which does not distract from the actual role-playing too much

Usually two house rules were applied, though : "Knowledge Religion" supplanted "Knowledge arcana" and the Favoured Soul always _knew_ the domain spells from one domain (picked at the beginning) in addition to all the other spells he could learn (say the fire domain, or the Healing Domain ... popular pick the last one ).
Oh, and we replaced the "wings" with a home-brewed list of individual powers depending upon the patron diety.


As for the Spell Companion - LMAO, for one, 70%+ of those spells are to be found in other sources (say, the complete books, FR-Material ) already, only not updated to v3.5, or re-calibrated text-wise. That is actually book to end the endless leafing about through dozens of supplements to look up the particulars of one specific magic.
Not much in there that is "unbalancing" , Actually some of the more bombastic and abusable spells (some FR things spring to mind ) have actually been left out. It basically just adds more flavour and makes it far more possible to play a "themed" caster than before. YMMV