Basically a mage casts what? 2 spells a run before he's useless by drain? (per the example)
Well, as I said, the example has stats picked to illustrate mechanics, rather than be good characters. Alice has a 3 in one of her drain stats - pretty weak. So I wouldn't read too much into that.
But we can fix that. Let’s make Optimised Alice. Bump her drain stats to 6 and 5 and her Sorcery skill to 6. And we’ll weaken Bob to the absolute lowest goon in the CRB, with all 2s for his stats. Then run it again.
Starting with her drain roll and working backwards: she now rolls 11 dice, so has a good chance of taking no drain from a non-amped manabolt, with its drain value of 4. But amping it would quite likely hurt her, so we won't do that. Her spellcasting roll is now 11 dice, for four (being generous) expected hits. Bob’s resistance roll is 4 dice, for one hit (again, being generous to Alice.) Net three hits. Bob takes 3 boxes; Alice takes none. Hmm. Not exactly overwhelming.
(BTW how is amping up a combat spell in 6e not the same basic thing as selecting the force in 5e? “Streamlined” my arse. But I digress.)
Let’s make Supercharged Alice. We’ll give her drain stats of 7 and 5, two levels of Initiation, and Centering. We’ll increase her Magic stat to 7 and a power focus at rating 2. We’ll also give her Increase Attribute at +4 on both her drain stats, sustained without penalty via Focused Concentration. That’s an impressive 22 dice, for an average of 7 hits. Let’s say she amps the spell twice, meaning she’s resisting 8 points of drain. Her spellcasting roll is now 15 dice, for 5 expected hits. Less Bob’s 1 expected hit to resist. Bob takes 6 boxes, Alice maybe takes 1.
Hmm some more. It's hitting hard now, but golly, Alice had to do a lot of work to get there. And don’t forget Bob is a compete schlub in this scenario.
Let’s say instead Ordinary Alice has an Ares Predator and can scrape up 6 dice in Firearms. She shoots Bob, with two expected hits. Bob’s defence test has one expected hit, for one net hit to Alice. Bob now rolls to soak 3P damage on Body 2, receiving 3 or 4 boxes of damage. Instead of facing drain, Alice has used one bullet.
I’m not seeing why Alice would ever spent five karma on learning manabolt.
Edit: forgot to add. In moving from 5e to 6e, when resisting physical damage, characters lost their armour, so dice pools went down from circa 12-20 to circa 3-6. Big step down. OK. But at the same time, when resisting direct combat spells, characters now get to add intuition to their willpower, approximately doubling their dice pool. This seems inconsistent.(In all of the above scenarios, Alice probably gets an Edge, but per SSDR's advice she is saving it up to buy off her stun damage.)
Reaver, you mentioned summoning. Let's look at that. We know manabolt has a drain value of 4 before amping up. When summoning, the spirit rolls Force x2 dice, and the drain value is equal to the hits it rolls. So that means, someone, somewhere, said "yes, this manabolt spell is correctly balanced at the same drain as summoning a Force 6 spirit." Which, honestly, what the fuck. This makes no sense to me at all.