Actually I think the "singurlarity Viewer for SL is quite wonderful. I had been using the Secondlife Viewer but it has always given me trouble with logging in and finaly just stopped working all together. After much failed attempts I have just gien up on it.
I myself do not have the money for a high end machine nor able to afford a internet connection. O I have tried Singurlarity and it works wonder full on my small laptop, barely crashes and runs smoother than any other viewer I have ever used.
The only worry I have at the moment is the rumors of SL starting to stop 3rd party viewers. If this is so, I would no longer be able to play second life due to there viewer not able to funtion with older machines.