The introduction of fixed deltas in portal activities is the worst thing that could be implemented. Increasing activity power through modifyers was way better since you could run basically any activity at a maximum delta of -20 (but usually at +0) and get the same rewards as you get now playing at a fixed -30 if you're at 500+. Also before the last update if you were at 500 you were encouraged to raise your power level so that the delta to get +2 drops would get lower but now you're fixed at -30 so there's no actual reason to aim for 550. If your goal instead is to just farm T5s you will get them at you power or at 499 but you'll still be forced to play at -30 or -25 when before the update you could play at +20 to +50 and farm T5s.