Positives:
+ Nexus 4 just fits in with the original Bumper
+ Hand strap does not look quite so cheap
Negatives:
- Of course, no GPS receiver in your pocket
- Tap-test (3 seconds under running faucet) failed: test paper inside was neat wet
Conclusion:
Before the occasional splash of water, the bag may even provided protection, but I trust there but rather the tested plastic bag.