On the August 31st Bombcast a listener wrote an email about the difficulty with quarter circle moves facing a certain direction on a D-Pad and asked if a fight stick would be better. 
 
For me, I'm the reversed. I have a Hori fighting stick, and I can't throw a fireball worth a damn if I'm facing to the right. I always seem to accidentally throw a dragon punch facing that direction. However, I have no problems with hurricane kicks rolling the stick to the left.  
 
Likewise, if I get turned around in the battle and face to the left, I'm a fireball machine but I can't throw a dragon punch or a hurricane kick. 
 
If I use a dualshock, I have no problem with these moves at all, but my thumb gets mangled and sore after 15 minutes of game time. I also don't like the button layout of the dualshock. 
 
I thought the madcatz fight pad would solve all my problems, and I bought one on sale at a going out of business Gamecrazy. Two of the buttons died on the controller after an hour of use. Madcatz never replied with a fix after they replied to me asking what buttons were broken. Gramecrazy wouldn't take returns since it was going out of business, and I read online reviews and said those fighting pads are pretty crappy.  bummer. 
 
Anyone else have these quarter circle problems in Street Fighter. Any recommendations?

When I first started I found it harder to throw fireballs from the left, because it just felt weird to move my thumb that way.  
 
Try just sitting in training for a few minutes constantly doing the motion to get your body used to it and get it in your muscle memory.  

When I switched to fightstick I couldn't do 2xQCFultras from left side of the screen. I just sat in training mode and told myself I wouldn't turn the PS3 off until I could do ultra from the left side of the screen 10 times in a row.. By the time I turned of the PS3 I could do ultras from the left side just as easily as from the right side. I don't think you should give up on the fightstick yet brozo. It was hard for me at first too but now that I can play with it it feels so rewarding.

I am completely inexperienced with the fighting stick scene. My Hori stick was reasonably priced and it worked on my ps2 fighting games. 
 
My stick clicks. Is that different from other ones? Could that have something to do with it?

" I am completely inexperienced with the fighting stick scene. My Hori stick was reasonably priced and it worked on my ps2 fighting games.  My stick clicks. Is that different from other ones? Could that have something to do with it? "

" @Jack268: Well, the stick I have is meant for the PS3. The box said it only works on PS3 and now PS2 games, but I have a back compat PS3, and I can use the Hori stick on some of my older fighting games like the Alpha collection.  Do all console sticks click? I'm just used to classic arcades, and sticks just rolled and sprun back to center.  One thing I am noticing in the training room is that I'm having such a hard time with two hit combos like Low Punch, Medium kick. I seem to be miserable with the timing. I've tried so many different timing combinations and I can't seem to get it right. If I do land the combo, it seems completely random. "

Just needs alot of practice man, begin slowly and just keep going faster.

To answer the original question, most sticks come with square gates which don't have actual indents for a quarter circle. Octagonal gates on the other hand have clearcut corners which makes it easier to do a QC movement. Thus a d-pad may in fact be easier for a square gate stick (most can be swapped back and forth), but I've heard it's worth just training on a square gate as they are more versatile since you can get perfect execution on one with practice anyways.

Sticks with a square gate will give people perhaps more difficulty with the quarter-circle motion at first. Now it feels really good to me, but it takes practice is all.

I have the Hori Fighting Stick 3. Playing with it now on my lunch break, I can tell it's a square gate.

I used to have problems with the motions when on the other side but got used to it. The only problem I have now is dashing left. When I'm using a joystick for some reason that double tap movement messes me up and about 25% of the time I'll just stand there like a moron when I meant to backdash. Really annoying but I'm sure I just need more muscle memory.

I never had that problem..

I had that exact problem at first,  couldn't do shit right to left, now i am pretty good, doing Akuma's red fireball still kinda messes with me though.

I use a FightPad and I don't use quarter circle characters. I tried Adon, but my fingers weren't having it.