Has anyone compared the low light performance of a GL1 vs the XH A1 in SD mode?

My impressionis that they are about the same effective speed at 60i but I would like to hear from anyone who has shot both in SD.

This is not scientific by any means...but the XH A1 fares much better in low light to my eyes (and monitor..lol). When boosting gain..the XH A1 appears to introduce less noise

I agree with John. Got both cams (PAL-Versions) and compared them side by side on a monitor. Low light performance of the XH A1 is much better.
Nevertheless you have to tweak the settings of the (at least: my) XH to get really good results in SD, especially regarding sharpness and coring.

A quick test with my A1 in SD mode vs GL1.
Based of Photoshop analysis of frame grabs from Premiere

Out of the box tests/settings (not adjusted for optimum noise, etc.)
In poor light (~60 watt bare bulb 24 feet from Macbeth color chart), that corresponds to an exposure of 1 second at f2 with ISO 320 film.
Manual mode, 1/60 shutter, adjusting gain and shutter
For same luma, A1 is maybe 1/2 stop faster.
Noise level about the same at 12 dB gain.
A1 image is noticeably sharper.
Color balance is close but you can see a difference.