Thank you for your inquiry and your concerns regarding our website.
There are no differences in the features of the low profile and the full height Intel® PRO/1000 boards except for the bracket height. We have combined the two and include both brackets in one package; therefore, the full height board is being discontinued as a separate product.
There is a ‘product compare’ section available on the site which provides the ability to compare multiple products, including the next generations of Gigabit adapters: http://ark.intel.com/products/family/46829/Intel-Gigabit-Server-Adapters
Here is a link to the Quad http://www.intel.com/content/dam/doc/product-brief/pro-1000-pt-quad-port-lp-server-adapter-brief.pdf
I would recommend comparing these three products for your next purchase consideration of a Quad Port Server Adapter:
Intel® PRO/1000 PT Quad Port Server Adapter Series (2007)
Intel® Gigabit Ethernet Server Adapter I340-T4 (2010)
Intel® Gigabit Ethernet Server Adapter I350-T4 (2011)
We apologize for any inconvenience. Intel is in the process of redesigning the website, and we are still working out the glitches. Again, thank you for expressing your concerns and we hope that we answered your questions to your satisfaction.