Poor antenna design on x9i, so I hacked it up and added an external antenna jack and made my own removable SUL external antenna.
I used MMCX connectors and 24awg bare wire cut to exactly 1/2 GPS radio wavelength (190mm or 7.48 inches).
Now I get 4-5 bars, 7-9 sats and 1M estimated error INDOORS! Outside it is awesome. It acquires faster and locks better.
I works better than other analog GPS's I've tried against known waypoints. Equally accurate but better performance.
This may be the smallest and lightest navigation based GPS out there. (Note: forerunners with sirf don't have baro, or mag compass)
I'm surprised it still works as I am not trained in any electrical stuff. I'm crazy when it comes to tinkering and I got a good deal on this ($89), so I was not too worried about crashing it.
Unit weight: 1.54oz
Antenna weight: 0.03oz
Total weight: 1.57oz
Here's some pics (shown with wristband removed, which I don't use anyway):
Unit and antenna.

Indoor use (when I leaned over it to take the picture I blocked some signal, so full bars are not showing).

Close up of connectors.

Sorry for the poor quality pics, but my good camera got dropped.

