What he said, I run the same exact setup. I'm at 644 ranged bonus damage, 1000 tech bonus damage, 76.83% surge, 28% ranged crit, 30.5% tech crit, 19,300 HP, and 1396 expertise. If I run a 1214 expertise build like the OP I have about 685 ranged bonus damage and like 1040 Tech bonus damage, but the survival difference between 1396 and 1214 expertise I've noticed is massive.
Mega those are really low stats if youre running 7/3/31 even with that extra expertise. You should take a look at your gear.
Also the difference in damage reduction from 1396 and 1214 expertise is less than 2%, so any 'massive' difference you are feeling is in your head, its not a big difference at all. Im assuming with that extra expertise, you are using expertise color crystals, you should switch those out for power crystals and youll be much better off. Trading expertise 1 for 1 for any stat, especially power is much more beneficial to you. The difference in damage reduction from 1396 and 1314 expertise is less than 1%.