Haswell has not been recieved with screams of joy from enthusiasts as we appreciate the power savings but are honestly more interested in MOAR POWER!  As an upgrade from Ivy Bridge there are only a few benefits but what about updating from an old Q6600 on an X38 motherboard?  That is what Legit Reviews just did, moving to a Gigabyte Z87X-UD4H and i7-4770K and as an upgrade it is more than impressive; everything from gaming to the productivity of the system skyrocketed as you can see below.  If you are still running a Q6600 on your main rig it looks like saving your pennies would be a very good idea.

more impressive benchmarks if you follow the link

"We all love doing computer upgrades, but sometimes we have to ask ourselves if a full system upgrade is worth it or necessary. There are times that you may only gain a small percentage of a performance boost, where there are other times that you gain significant increases. Today I am going to compare my original Intel Kentsfield CPU and X38 motherboard to a shiny new Haswell CPU and Z87 motherboard."

Here are some more Systems articles from around the web:

Systems