If you import yourself into WrathCalcs and switch the pieces around, you should be able to tell quite easily what's best for you. I know swapping my 496 gloves for some 522's broke my T14 4-piece but was still a DPS increase.
I have absolutely no idea how to work WrathCalcs lol.
The only two pages you'll really have to worry about are the first two: Gear Setup & Main. To import your character (talents/gear):
1) At the top of the Gear Tab, enter your character's name and server into the blue boxes.
2) On the right side of the same tab under "Import Details", change your region to whatever game region you use
3) Hit the Battle.net button to import your character.
You'll notice all the gear will fill in automatically, and the same with your Talents on the "Main" tab. It should also display your DPS in the top right corner of the Gear Setup tab.
To change gear, all you need to do is click one of the blue names where your gear is displayed and a drop-down menu will appear. Select the piece of gear you want to swap in, and you can do the same with swapping in gems/enchants.
The main Gear Setup page has a good amount of information around the page to direct you to what you need to know.
I would drop the 2 set if you have enough gear to make the 5k haste breakpoint without trying to get more haste take my druid for example (barciana on burning blade) i droped 4 set for 2 set i have the crit trink from animus and the VP trink
I am still able to hit the 5k haste break point with a couple hundred haste over plus i end up gaining all the crit haste mastery int and what not from the higher ilvl gear that will greatly pass the extra 2 sec on dots thats not counting my 2 piece even so droping your 4 set if you can make the haste is more then worth it
Yes im just showing that still reforged for all crit even after dropping a haste trinket I passively have 5568 haste not reforging into any or out of any so reaching that break point is very very easy.