Although I do agree that the current Allagan set favors Det more then Crit, it also makes it so pie is the other secondary stat on every single piece, take a look:

Weapon - Speed & Pie
Head - Det & Pie
Chest - Det & Pie
Hands - Crit & Pie
Waist - Speed & Pie
Legs - Crit & Pie
Feet - Speed & Pie
Neck - Det & Pie
Ears - Det & Pie
Wrists - Speed & Pie
Ring - Det & Pie

Leaving us with a total of:

5 Pieces with Det
4 Pieces with Speed
2 Pieces with Crit
All pieces with Pie

So the new pieces from Coil may be a mixture just like these, hopefully more balanced. However this also raises another point. The Relic +2 so to speak, was said to eventually have stats you could change into basically whatever you wanted. So if you want Det+Pie you could have it, or Det+Crit, or whatever combination you prefer. It makes me wonder if the new coil gear will eventually have the same option.

Mind is still the #1 stat over the others, even going from ilvl 80 gear to ilvl90 the mind added makes more of a difference then the measly amount of det, speed, or crit you lose on that particular piece. We'll be going from ilvl 100 with the new tomestones to ilvl 110 with the new coil gear, and you'll pretty much want to upgrade due to the increased mind. Not to mention who knows how much HP we'll want at the end-game. Personally speaking though, full ilvl90 gear now (with the allagan weapon) puts me at 4200+ with just the party Vit buff and no food. Which is just enough to survive a fireball from Twin. So I get the feeling you'll need all the coil gear you can get regardless of secondary stats.