They both have the same model sensor? s
Philips Twin Eye it is on both, yes.
prefer my DPI to hover at least around 3500 as I don't like having to move my mouse all over the pad to get my cursor to the other side of the screen.
At 1800dpi you have to move your mouse 5cm to reach the other side of the fullHD screen, thats done without moving the arm simply by moving the wrist.
You tell us you use 5600dpi with 3/10, that should be the same "speed" as 3500dpi on 6/10(1::1 pixel/movement) or even less.
I still have 25 days to return my mouse to the store for a full refund if I have to and I have a two year warranty on this mouse. If I have to return it is there a mouse anybody recommends for me to try?
Id say return it.
You bought 2mice with laser sensor with acceleration, if you dont care about gaming performance the G500is a mouse for you. The ADNS-S9500 has positive acceleration, but for mmo-stuff and desktop its an awesome mouse with a lot of buttons and high e-peen (dpi). The G9x is about the same but more expensive and different shape.
Thats about the same performance you get with the mice you bought for half the price.
If 3500dpi are enough(they SHOULD be unless as i said earlier you have 3monitor each 2592×1944 setup you can choose one of those for best performance: