It depends on what you mean by "competitive".Channeling needs help to be competitive, unless it’s not supposed to be competitive.
Channeling was originally designed to be a replacement for Celestial wands. Wands were NOT intended to be a primary focus of Celestial casters, they were designed to be an addition that gave casters more to do throughout a day albeit at a lower level.
Channeling allows more flexibility than that, but its ultimate goal is to be there to allow casters to do more throughout the day, just like Wands originally were. Don't get me wrong- Channeling absolutely gives way more flexibility and focus opportunity than Wands ever did, since you can specialize in Channeling if you really want to - but the primary purpose of Channeling is to give casters more to do throughout the day, primarily in terms of "quantity of packets to throw and interact with combat".
My personal expectation is that a few purchases of Channeling will give casters a satisfying mechanism with which to throw some 5s or 10s (which are significantly more potent in 2.0 than the same number would be in 1.3) and help contribute to the combat while waiting for the right opening to use their spells. One or two purchases of Channeling per column of spells "feels" right to me, but YMMV. Spells will absolutely be more impactful on a fight than a single Channeling packet will be in the huge majority of cases, and that's OK. But for the purpose of giving players a mechanism whereby they can make regular, useful contributions to a battle without expending their limited spells, Channeling provides an additional outlet that may not be duplicated in pure spell memorization.
So: In terms of "pure power" in a vacuum, you're best off memorizing nothing but Storms all day long, sitting in a chair, and waiting for the fights to come to you. In the Real World (or at least at events), however, Channeling is intended to provide a useful supplement to spells so players have more to do in a day than what they would be limited to with their spell slots. At this purpose, IMO, it excels, and gives something that spell slots just can't duplicate - sustained small plinking for an extended period of time while having complete freedom of movement and ability to swap to spells in between charges when you need to. Storms can't do that. Spell slots alone can't compare for that purpose, either.