OP's 2nd account here, just wondering how the crit gemming compares to the sp gemming dps wise. Big difference worth knowing about or not a huge deal?
Comparing myself to spellpower-gemmed mages, as well as having switched back and forth between the two kinds of gemming multiple times over the past few months, I can honestly say that the difference (if there is any) is extremely tiny. And if there is, it is probably slightly in favor of crit-gemming. The extra 4% crit on paper provides a roughly equal gain to the 200 sp when you factor in crit scaling for FFB (on avg, FFB crits for 3.3x and Pyroblast crits for 2.5x regular damage). But then crit has the added bonus of also noticeably increasing your hot streaks (due to exponentially increasing hot streak procs with rising crit - that's just hot streak's design), as well as granting higher 2p T10 uptime.