Thanks for the info, and certainly the comments for the wife :-).
I'd appreciate it if anyones actually got some "hands-on" experience of using both camera's. Does having a party mode mean good low-light focus? Is manual focus available because low-light focus is a problem? It's the actual user experience and when problem do occur I'm trying to get a grip on.
These are 2 very low light action shots, well, one is anyway.. There was a porch light behind me and the rest of the light is the on camera flash.. Both were taken using the af assist lamp to aim the camera and the camera did the rest. I don't think you can get much more extreme in low light than 2 black dogs. The top photo is resized only, no crop, and has had an autolevel adjustment in photoshop.
The only problem you are likely to have with low light focus, is no light. That's been my experience anyway.. I Will say that in the case of the top photo, the only real difficulty was seeing what I was aiming the camera at. However, with the AF assist aimed at one of the dogs, I managed to get about 30 shots in about 5 minutes (it was too cold to stay out any longer).
I use the manual focus mostly when there is a detail that I want to make sure is In focus of a particular photo.. such as..
Taken at midnight. With the flag blowing in the wind the camera wanted to hunt for a focal point.. Both manual focus as well as switching to spot auto focus solved the problem. Several shots were taken, some better than others, this is just one of them.
Edit: Almost forgot.. The scene modes (such as party) don't change the capabilities of the cameras. They are simply presets of options already available to you.. Personally, I rarely bother with them.