Gauss has a much MUCH higher velocity, making it easier to hit fast moving targets. This is especially true on when the server is starting to lag (Since the delta between where your PC registers the target, and where the server registers the target are greater).
Furthermore for people who can hit the the same spot over and over again, the Gauss is preferable since it is doing more damage to the target location. At 900 meters, you are better off sniping with ERLargeLaser and Gauss than the ERPPC. I'm not saying it cannot be done, I'm not saying ERPPC is ineffective at sniping, I'm saying Lasers and Gauss are better at by design. The CERPPC is better for when you have 2 more more people shooting at the same target. You both won't hit the same spot, but with the splash damage you make up for it.
IMHO the balance between Gauss and CERPPC is just fine.
When you bring HGauss, PPC, and LGauss into the discussion is when there are some questions (DPS, Ammo, Heat, etc). But I feel the overall concept of "Splash does more damage overall, but less to a specific location" is a good one. The devs got that one right.