It was comfortable to hold yes, but the buttons were crap and their placement even worse.
Comfortable to hold, ok at least you recognise the ergonomics, one argument we won’t have to have, but button placement? The gamecube controller was designed to be intuitive. There’s a big green button, designers please make the principal action of the game revolve around the big green button. The cancel button should be the small red button, easily found when you want it, but slightly more difficult to hit to avoid accidental usage. Its also good for actions that you might think twice about using i.e weapons with limited ammo, brakes in a racing sim. The X & Y buttons are at 12 and 3 to the main button, easily found with out looking so you can play for longer without having to look at the pad. The shoulder buttons have varying levels of response so that they can be pressed accidentally a little (ever noticed how inexperienced gamers often squeeze joypads?) and then there’s a 3rd shoulder button for whatever you like. and the d-pad and j-stick are within easy reach of eachother. and the c-stick is in easy reach of the main button cluster
Yes the d-pad is too small, no it doesn’t have as many buttons as the competition, but all the control methods are independent of eachother, using the j-stick is not simply alternative to the d-pad (although it can be if you want it to be) and using the c-stick is not an alternative to using the buttons.
Simply put the gamecube pad was designed for pick up and play. The proof, to my mind, is in wario ware. The only game I’ve ever known where you can hand the controller to someone who has never played games before, be asked “how do you play this?” and reply “you’ll see”. And they will pick it up. SOmething happened! What will I do? I’ll hit the big green button! oh I was too slow, but my character reacted I’ll try that again.
P.S. If you have issues with the dreamcast I hope to god you’re not going to try and claim there’s merit in the X-Box controller