"If there's no purpose to the analogue, and it just makes inputs unnecesarily long, like in fighting games, then I go with the D-pad.."

I basically view it the other way around.
If its unnessary long to do on a Dpad with taps, and fine grande control from analong is faster, then its better than the D-pad.

Else..... use the darn D-pad :)

2.5D is a myth. It doesn't exist. It's just 2D rendered in 3D. There's literally no mechanical difference.

D-pad is more precise, so I'd choose that mostly for 2D games

Analogue has more directionality so it's good for 3D games

but of course, this depends on the game itself

2.5d? Like Crash Bandicoot? That's what separates 3 from 1 and 2 in that series. The analogue is so much better for controlling. For 2.5d like DKC I'll take Dpad (though I like Sony's Dpad more than Nintendo's this gen)

Depends on the type of game, I used Dpad for Rayman Origins/Legends on the Vita. Anything I played when I was young I used dpad though and still do, pretty much every ps1/ps2 game (CTR, Wipeout Fusion, Spyro the Dragon) where it's possible to use d-pad.

Now It's very rare I don't use analog.

As everyone said, depends on the game.

For the most part, I prefer an analog stick, but for things like 2D platformers and shooters, D-Pad is the way to go.

Dpad is better

Dpad only for side scrollers and fighting games. One of the reasons why I prefer the Dualshock.

Edit: It depends on the game; I don't have a preference.

When playing Ori, I switch between them both depending in what I am doing in the game. Overall, i prefer D-pad though.

2.5D I think it's games like little big planet. It's mostly 2D but the layers make it more while not making it a 3D game.

Though bringing those games up is pointless fur this discussion since the d pad only controls expressions in little big planet