Actually, FC does cover when Mages get spells - every time they pick up a rank of Spellcasting they get another spell.
I am busy trying to convert two campaigns to FC - one from Spycraft 2.0 (easy, except for the gear system) and a homebrew (much more involved, since I am converting form D&D 3.X).
Both are using Elements of Magic for the spell casting, so I can't comment too much on FC's magic system. It looks workable, I just like EoM: ME better.
The biggest advantage, by far, is that the adventures are not necessarily tied to level - that they can be scaled on the fly. I can say that the NPC/Monster system is pretty darned awesome.
I like being able to pit a second level party against a giant and not have to worry that it will all end in tears. And because of the way NPCs work they scale relative to the PCs - so an NPC that can clean their clocks at first level can still do so at level ten.
For the homebrew in particular it means that I can scale an adventure when the PCs get to it - kind of important since it is a fairly open setting in regards to where they go. This allows me to place some adventures by area, rather than having them travel from job to job, adventure to adventure.
This was something that I also liked in Spycraft 2.0 - when I was planning out my Fallout 3 campaign I was able to allow the PCs to just wander where they willed, tying adventures to the locales ahead of time - so the ghouls in the tunnels beneath Disneyworld did not need to have the PCs dragged from Cape Canaveral in order to confront them. Whenever the PCs get to Disney will be just fine.
It also means that I can create some Adventure McNuggets that I can drop in when needed, without a whole lot of work. I can spend some time to do up some short adventures/encounters that I can just drop in when I am bored/lazy/have no idea what I should do next.
I am even converting an adventure that I have run under several systems, from Runequest 3 to AD&D 2, to Warhammer Fantasy Roleplay. (I am not sure it really counts as converting - my original notes are systemless.) A Tree Grows in Aidentaugh. (Tree in the sense of Tyburn Tree....)
I am liking it so far, and should be ready to run the first games in my old homebrew in November. Right now I am enjoying some time as a player in a Spycraft 2.0 campaign.
The Auld Grump, sleep typing, again....