So, I've been keeping non-usual hours in SL, lately. Most of it is due to planned and forced vacations - I can do a work-day with 4 hours of sleep, but I cannot survive a full-day with my children. At your expense, we're having a blast. Just thought you should know.
To compound the issue is this Dell Latitude D630 laptop: normally, I order models with the upgraded nVidia graphics chips. In these desperate times of cost-cutting, the company has decided to configure the laptops with the less-expensive intel integrated graphics chips. Herein lies the problem, as the integrated intel chips seem to have an issue with SecondLife. Just a few minutes after teleporting in, the cpu hits 50% and lag makes the entire experience unworkable. It seems to be related to sculpts and scripts, as my sandbox seems to give me adequate chat-performance (but the conversation is less-than-stimulating there).
So, anyone considering a hardware purchase, I strongly advise the ATI or nVidia adapters over the integrated intel versions - for a better SecondLife.