Couple of comments:
The keyframes are extremely difficult to grab onto. You have to click exactly on them to move them around and I often find myself repeatedly clicking on them trying to hit just the right spot. Either increase the size of the keyframe dot or expand the area around it sensitive to the mouse.
Jump to next keyframe button needed. (or at least I didn't see it)
As near as I can tell these curves don't have any kind of handles on them to adjust the TCB. This makes smoothing out animations difficult because you need to add keys to force the curve to do what you want which can create other problems.
Having to activate a channel before you can edit it first is a pain. If I can see a point on any curve, I should be able to grab it and move it. Having to click on the appropriate channel letter first and then going back to the curve editor after to move the key slows down the workflow with a lot of unneeded mouse clicking back and forth between the channel box and graph editor.
Hot keys, similar to Maya's animation editor would be great. In fact, as Maya has become an industry standard for animation, copying their hot keys would be useful and intuitive to animators, so for example highlighting a key, hitting W, (for translate) and then moving the key without having to then again click right on it would be awesome. Having the option to constrain to an axis by hitting the CTRL key would be useful too.
Overall the editor gets the job done but it just feels very basic and lacks the polish and depth found in other packages. I'd rather see other things in TG added first, like wind effectors on plants, but since you asked for feedback that's my $.02 for what it's worth.