So I got my guy to tier 5 and received Thicketmaster as one of the random classes.
All I can say is wowza; I literally ran through the citadel area shooting directly in front of me and destroyed everything without even aiming my shots. It essentially fills the entire screen area in front of you at rapid-fire speed, cooling down more than twice as fast as the shattered spells.
I understand Thorn Mass Penta - since it's slow by default and has a high cooldown time, five shots is justified as a knockback wave. It essentially becomes the penultimate defensive spell, either killing or knocking back anything that gets in your face, but is too slow to go on the offensive with at a range.
Thorn Burst Penta is insane though. A lot can be said about a consistent, fast, long range and accurate straight shot that was Thorn Burst; its problem was the complete lack of complementary utility spells, which was solved by Thorn Mass Penta. Quintupling Thorn Burst put Thicketmaster from the bottom to being solidly on top, literally clearing out whatever side of the screen you are aiming at, like a rapid-fire "smart bomb".
If you do end up tweaking the spells at all from the update, I think nerfing Thorn Burst Penta back to regular old Thorn Burst might be a good idea. Still a powerful, go-to option when you have line of sight and know how to aim, then you save the slow Thorn Mass Penta to defend yourself from enemy spells or repel incoming, slippery fliers. As a single shot, it's not derisive from the three-shot blast spells and not world-dominating like the Penta version.
Thorn Mass Penta was really all it needed to remedy its weakness, then Thorn Burst Penta put it way over the top. I think you may have been a bit overzealous in the revision :-).
Edit: I think Beastmaster is perfect now though, and the charge shots are much more useful and satisfying.