Not exactly an apples to apples comparison. The V1 is closer to Canon's G5. I have both the G5 and the S-50. I considered the V1, but two things put me off the most: the bluish cast that shows up too often on V1's, and the Memory Stick. I really wanted to be able to have compatibility in memory with a D-SLR when I get one. Otherwise, the V1 looked really good. I also have a Canon Elan 7N film SLR, so the flash compatibility was an issue there as well.
The V1 has a dedicated hot shoe like the G5, the S-50 does not. The V1 has a wider focal length range than the S-50, more like the G5. Thge G5 has very good battery life, like the V-1. The S-50 has lower life, although on a recent trip, I never used up a battery in one day. But you ought to have a spare anyway. Sokmething to check on: does the V-1 recharge the battery in-camera? The G5 does and I had to buy a separate charger. But the S-50 comes with a seaparate charger, so you can use the camera while charging the spare.
The S-50 is a little large for a pocketable camera, but it's got a slippery shape, and goes very well in pants and jacket pockets. On trips I find myself going for the S-50 first over the G5. The V-1 is small, but not a slippery shape, and won't pocket as well. Also, the sliding cover on the S-50 is excellent for pocketability and provides better lens protection.