You mean Ken Hood's system? Been working fantastically for my group. For the most part, spells function as written... we've changed a few to fit the new system though. Magic Missile now counts as an auto crit... so soak still applies, but you get to choose the critical effect of your choice (generally bypass some form of soak, since otherwise no damage will be dealt and thus no other effects are possible). True Strike now grants you UP TO a +20 bonus to your next hit, not to make your attack roll exceed the defence roll by more than one. This keeps it true to the purpose of delivering touch spells without it granting you +20 to damage as well, which is insane for a level 1 spell, even NOT in the GnG system.
I think those are the only two problem spells we've hit so far, other than continual damage stuff. For anything that deals continual damage, it deals normal damage round 1, then normal damage + normal damage again for round 2, then normal damage + normal damage + normal damage for round 3, etc. (If it's a continual acid attack, 1d6 per round, then round 1: 1d6. Round 2: 2d6. Round 3: 3d6. Total of 6d6 damage rolled over three rounds.) This makes getting through high soaks possible. Energy resistance also applies increasingly each round, so red dragons can still wallow in lava if they want.