Flunky,
Old manic Shmups and bullet-hell Shmups are definitely different beasts.
For one, manic shooters are all about bullets that are fired directly at you at higher speeds. Bullet-hells are all about patterns and tiny "touch movements" through slow blankets of bullets.
In maniacs you have to lead enemy fire a lot, and mainly require more sweeping movements. While bullet-hells are about labyrinth path-finding through a patterned sea of bullets. Small finite movements are better here (prime reason I like the shorter throw, quick actuation joysticks for Shmups).
The jury is out on whether I like manic or bullet-hells more, but in any case they're definitely different and require a bit of a mental shift at playing. That being said, I don't think gunbird or dragon blaze is good examples to jump into the genre. DB for sure, it's waaaay hard to play.
Try out the first donpachi, or dodonpachi...they're a bit easier to ramp up for.
Also, the Strikers series is a good balance between manic and b-hell.
*edit: while you're at it, check out Progear No Arashi. It's difficult'ish, but the game is just absolutely gorgeous looking. I credit feed it just to keep looking at it.
