I remember right arrow on 2P sucking and it might have been fixed, not sure. 1P is fine from what I can recall. But not sure.

Erm, that's DDREX anyway. ITG is hopeless.

DDREX pads depend on when the arcade operators come in and do some work on them.  ITG pads are fine, but the machine itself is borked until they fix some of the innards.

If you want to be safe, just play on the 1p side.  Chances are someone had already experienced faulty pads and reported it to be fixed, so you'll noticed a sign on the machine itself.