I see that you don't "feel" the CAVE stuff. You should check out Ketsui though.
I watched you play ketsui (thx for introducing me to this game, looks awesome) and your hand eye coordination is crazy! Are you that good or did it take you a lot of practice to get that good? The enemies spray so much bullets and there is hardly any space to manuver, no room for error, I'd impale myself immediately. Wow!
While I'm "pretty good" at shmups in general, I've played Ketsui A LOT. So I know what I'm doing most of the time. But while there are many, many bullets, not so many of them are fast, and the hit box is that white strip on the top of your helicopter (yeah, it's not a plane). Also, the scoring system of the game encourages you to take risks. I've managed to get to the 5th boss (last) about 20-30 times, but only cleared it once (on the Japanese 360 port) because I never use training mode or save states.
How to play
Ketsui (basics):
Tap A button for wide shot, hold it to have your options lock onto enemies, causing you to slow down and make maneuvering dense patterns easier.
Press B button to fire a bomb - if you are locked onto an enemy with LOCK SHOT the bomb will hit your target.
Hold C button for full auto wide shot - kill a smaller enemy up close to get a large value chip, preferably one with a 5 on it, then hold A button to "cash in" on that value from everything you kill until your counter runs down and you start getting 1-chips. When that happens, kill something small with wide shot then hold A again. If you look at my video, you'll notice that I kill a small tank with wide shot just before finishing off the first mid-boss and getting 5-chip from it.
If you don't play for score, you won't get the two score extends at 20 and 45 million points, so at least trying to get as many 5-chips as possible is recommended - and fun! There are lots more nuances in the scoring system that's pretty hard to master, but you can and will enjoy yourself while playing the game as you can play it pretty much any way you want. You don't have to pick bosses apart, section by section, just locking your shots will kill it eventually.