After I run a few runs with the mage/ritualist character I created, and after playing around with the magic rules a bit more, I want to work on writing a custom ruleset for Ritual Magic, to fix it up for a Shadowrunner type of playstyle.
As was pointed out too earlier, it takes far too long to cast Ritual magic, and the same time to cast a powerful or weak spell. Another problem is that while you can cast high force spells this way with multiple casters to get more hits, you much each resist normal drain as if you were casting the spell, severely limiting the extent of your spells. I plan to make a system that essentially uses these factors to determine casting time and difficulty, following this sort of path:
1. A low base time for the ritual, calculated from your magic and initiation score. Being more initiated will make things go faster, even if you haven't re-capped your magic. You have to roll your Ritual Magic test against a threshold to determine the rest of the time.
2. The Ritual Magic threshold will be calculated with the Force of the spell and type of the spell taken into account. Combat spells, for instance, will have a higher threshold modifier then Detection spells.
3. You may add additional spells to a Ritual casting to form a compound ritual. There will be a short bit in the rules on how to calculate DVs and how to add thresholds together to get a final Ritual threshold.
3b. I'll probably also work in other modifiers to the Ritual for various effects. By making it tougher to cast, you could reduce additional drain, for instance.
4. You begin the ritual, expending the required ritual goods. You then begin the assisted Ritual test, rolling to beat the threshold of the Ritual, you may use Centering and any other metamagics to lessen the drain. Technically these must be done before hand, but presumably, you'd work these into the 'ritual commencement' stunt, before settling into your 'charging the ritual to beat the threshold' stunt.
5. Detection tests apply as normal to the target. May adjust them accordingly as needed. Again, different spell types will probably be easier to detect.
5. After you beat the threshold, you make the appropriate spell tests (using assisted casting if appropriate), and resist the combined Ritual Drain, with Overcasting applying as normal to make drain physical.
It's still just an idea, and things need to be hammered out, but making the threshold and timing for Ritual Magics be additive instead of subtractive allows more complex and varied Rituals to be created, and means that doing a very simple will be appropriately easier and faster to perform, without making overcast uber-combat spells terribly easy to sling.
