Diddy seems to have so much variety, I don't even know. Some matches I go crazy and have two naners out the entire match (although that's rare) and some matches I only pull out a naner once (more likely).
As a very rough estimate, half the time I have a naner out and half the time I don't. But it really depends on the stage. On a stage like Yoshi's Island, I don't feel comfortable at all with naners. On FD, I usually at least have one, sometimes two. On Battlefield, I'm fine without them or with only one, but I'll never have two.
Also depends on the character. I obviously don't naner spacies as much as I do Boozer.
I usually hate having two naners out for long periods of time. Maybe once a match there'll be a 10 second burst where I go crazy with two, but if I leave two naners consistently on the stage, I don't focus as much; my mind steers away from "how is my opponent reacting and what's my best approach and what should I watch out for," to "LOL THROW NANERZZZ THROW NANERZZZZZZ."
Diddy's got a pretty solid game without naners anyway. I rarely start a match plucking up a banana...I usually don't even use them until halfway through my first stock--his dash attack setups are too good. After the easy early 40% or so is when I pluck out a naner and make my approaches easier. Makes for some nice, flashy, and often overly-flashy setups too like glide toss to dtilt, glide toss to dsmash for a kill, near the edge a single naner lock but instead of using dair to recatch the naner I use fair (gotta thank counteh for that idea) etc.
tl;dr: I usually go with one naner out at once, but I'm perfectly fine without any if I have an opponent who actually picks them up and glide tosses back, lol.
