4GB DDR3 vs 6GB DDR3, worth extra $100?

Hello, would 6GB DDR3 vs 4GB DDR3 have much difference in laptop to be worth an extra $100?
Somewhat desperate to replace my 6 yr old vaio, and the two models I'm comparing are Toshiba R835-P81 best price $799) and R835-P84 (best price $699). I was looking for the R835-P70 which is out of stock everywhere for a while so these are my two options. The only difference in my limited knowledge that can see is the 4GB vs 6GB, would it be worth the extra $100? Both 64 bit.

Thank you!
http://us.toshiba.com/computers/la [...] 0/R835-P84

http://us.toshiba.com/computers/la [...] 0/R835-P81

No.

You would have to be running a couple of those applications that are known for using lots of memory. Going with 4GB is a great place to save money, and you won't notie the "loss".

That is a huge price difference for 2gb! Unless you are a heavy multitasker, it is probably not worth it.

It is not clear to me if there is an open ram slot on the cheaper unit available where you could easily add ram later.

I would save the $100.

You can buy a 8gb kit of laptop ram for $50 or so, and replace it all if necessary later.

Definitely not worth it. After all, you CAN replace that ram for a higher one later, and for cheaper, right? Based on those links, looks like the higher one is a magnesium alloy, which would in term make it stronger, and more durable, right?