lvl 39 Grav/Psi here. (SOB)
A few things I'd point out. The grav AoE and single imobs in the grav line do not negate knockback or the flop ability from ice as you said in your guide. I use imobs followed by propel and it sends them flying everytime.
While I remain disapointed with Psi in pvp, I've had great success with grav. Vs squishies I start combat with lift, followed by propel, then crush for the -fly/slow so they cant get away, then the hold, then go to work on them with damage. Right before they come out of the hold start the chain over. I can keep defenders/controllers/blasters on the ground and or held the entire fight. Its all about timing, and grav offers an 2 excellent damage dealers (lift and propel) that keep the target from attacking back, on top of the hold I also have. Gravs AoE attacks/holds really blow, but single target wise its quite excellent.
On a side note Wormhole is VERY useful in pvp. I've learned some really brutal tricks with it hehe. Using it to port hero's into gun drones to thin out base camping is unbelievably powerful. I recently ported 5 heroes at one time into our base and they were all killed. It also significantly increases the range of single base tp foe. Most hero's know how close they can be without being in danger of tp foe into drones. However, I can tp foe to me, and while its charging, prep wormhole. As soon as they are tped to me, I wormhole them into the base, effectively doubling my drone kill range.
The not so morally questionable strategy is using it in your attack chain to increase fall damage. Here is what I do. If you come across a flying target fly over them, use lift to bring them close to you and do some quick damage, follewed by crush, followed by a quick wormhole straight up. Crush will -fly/imob/slow, wormhole throws them straight up another 100 yards, then they plumet straight down right past you. Toggle off fly, drop almost to the ground, and toggle on hover. You will take no drop damage while they take a ton. In all cases thus far with this strategy they will not have moved as the disiorient from wormhole, or the imob/slow from crush will keep them there. I usually arrive a second or 2 after they hit the ground anyway. I arrive, slap on my hold, and finish them off with damage combo. Takes some practice but is insanely fun and boggles the mind of your target.
