Soaring Rake is a mobility based PP, which is often an odd duck to figure out. The goal is to let you fly. The attacks are just excuses to fly, which makes them likeable if you want to fly, less impressive if you want to actually impact the enemy you hit. Sure you flew without provoking, and at one point you did 2[w], but so what? With CA its something a rogue _could_ want, but it goes down hill from there. opinion: just damage isn't worth even a hexblades time (+dex to dmg), when you could be gaining invisibility or a bonus to defense. In the end its less combat worthy that an unstanced powerstrike at level 1, you just got to make it in a flashy way. Similar story for the daily. you make a boring attack, and for some reason now people can fly. Why? Because its an attack AND its a movement based PP, thats why. They exist for the effects they provide, which makes them feel like utilities, but require you make a diminished combat contribution to activate them, which makes them feel diminished. Thats my complaint. As much fun as flying is, combat should not be ignored.
And if it is to be ignored (or just diminished) you'd better be getting something in return. And in a mobility based PP what you should be getting is mobility. And to my eye it is hard to claim this doesn't give you mobility. You have mobility coming out your eyeballs, dripping off you like pixie dust. If you want to fly often and not rely on items or being X class that gets wings/flight, this gives you that chance. And flying is really good. I've seen it in action, and at times even with my at will teleport of 7 at epic I've thought "I wish i could fly".
To complain that you don't gain permanent fly speed, feels incorrect. That's a [very] valuable thing, you just don't give it away for nothing; sure, you're more of a Flitting Rake than a Soaring rake, but flitting (let flitting= flying where you must land) is really useful. You just don't treat it the same as you do a fly speed. With a fly speed you're all "I'm hovering/circling 40 feet up, i'll shoot the mage with range 10" or "I charge the flying dragon". This is nice and cool and something that is worth obtaining. But flitting is also good. You'll only kill yourself falling if you're foolish and ignoring your acrobatics and halving of fall damage the PP gives you.
On a simple level, its similar to teleport, you can ignore difficult terrain, jumps, climbs. In fact, you can fly places you can't teleport to because you can fly around corners and what not. (teleport is all around better, no question, but you'll notice that teleport speeds are even less common than fly speeds, and a PP that simply replace the word fly with teleport in this PP would be insane beyond belief). Flitting is better than walking, better than jumping, better than climbing. It is an upgrade to movement, and one that others will be jealous of if you have a chance to show it off. The use for flitting is to see be able to get to any square in your movement range, going over enemies, fences, chasms with ease to get yourself to the precise location you want to be on the ground (Not hovering over the battle). Teleport does it better, but the investment cost is VERY high (expensive item-wise to get a range equivalent to your speed, assassins and warlocks have the market on doing it reliably at will). This is good movement at a good price.
I've seen enough 'flitting' about to know that for a mobile type character, this is a useful tool, very useful. I would take this PP for a mobility based character with a fey flying feel. My complaint about the attack powers stands, but I would still enjoy playing this PP immensly.