i'm an S95 owner. Never seen/played with the TX1 but based on specs, it seems to have a smaller aperture than S95.

Aperture : Auto(F3.5-F4.6)

S95 has 2.0 aperture at widest angle. This means that it allows more light in, which is good for night shots. So far, based on my experience with S95, I find it very useful to use Av mode and fix the aperture to 2.0 then allow the camera to select shutter speed. The other day I managed to get a good night shot even without flash this way.

you can try this website:
http://www.imaging-resource.com/IMCOMP/COMPS01.HTM

and select S95/TX1 for comparison. Perhaps look at indoor ISO800 (night shots will most probably be shot at ISO 800 upwards), and compare. look at the crayons/pepper shaker and you can see the difference in noise level between the 2 cameras.

good luck! i love my S95, only complain is no autofocus/zoom during video...

I bought it at Digital Mall DY Divine. Skydrake shop, he got another shop at Times Square too.