Believe it or not, the situation for mundanes vs. mages has actually
improved since SR3. With a fixed TN of 5 and hits capped at Force, spells are less likely to instantly kill you. Plus, if you really need to, you can spend Edge (so can the mage, obviously, but magery is pricey, BP-wise, so mundanes might tend towards having it slightly higher). Plus, now that counterspelling is a separate skill, friendly mages are likelier to actually use it on you, rather than saving the dice for spellcasting.
As someone who played sorcerers a lot more in SR3, I'll tell you - spellcasting was deadly. You could get a specific spell focus at Rating: 6, +3 from the Dragonslayer Totem, get 6 from sorcery and 6 from spell pool, cast it at 6D, and you would be rolling 21 dice against someone's Willpower. And if you got even one net success, they were dead.
QUOTE (Cain @ Dec 11 2008, 12:32 AM)

They just get the one resistance roll. It's not quite as bad as it sounds, but it does mean a Counterspelling mage on your team is essential if you expect to survive intense magical opposition.
That, or get a gnome with SURGE II - metagenetic improvement/Willpower for the positive quality and astral hazing for the negative quality.