Heatware ~ 194 ~ 100% since 2005
Ebay ~ 387 ~ 100% since 2004
G.SKILL 16GB (2x8GB) Laptop Memory Kit (Model F3-10666CL9D-16GBSQ) -- $99 shipped
$135 shipped at Newegg
**This kit is a 204-pin, DDR3 1333 (PC3 10666) laptop memory kit. I've used these for about a year and I've never had any issues with them.
Phoronix: G.SKILL 8GB DDR3 Laptop Memory On A Linux Ultrabook
With my purchase last month of the ASUS Zenbook Prime as a new Intel ultrabook for carrying out some development work while traveling, the only two traits of the system that I didn't like were the use of an Ivy Bridge processor over Haswell and that it had only 4GB of DDR3 system memory.