What is the read/write speed difference between them both?

I'd go for the samsung 850 pro, it has better max read/write then the intel 730.

I seen that. Awesome deal but, I don't trust it. I remember reading about a new firmware fix for some kind of data issue? Some say it worked others says it did not. Tbh. I am completely torn between the Intel 730 and Samsung 850 Pro. Ugh. 3rd world crisis!

FattysGoneWild
I seen that. Awesome deal but, I don't trust it. I remember reading about a new firmware fix for some kind of data issue? Some say it worked others says it did not. Tbh. I am completely torn between the Intel 730 and Samsung 850 Pro. Ugh. 3rd world crisis!

The problem was for some reason data older then 30 days was reading at a slower speed, somewhere around 275 mb/s instead of 540 mb/s ish. To be honest I didn't even notice the speed drop and wasn't aware of it until I saw the thread about it. It did show up during some testing and I can say the firmware fix did correct the problem and did not damage any data on the drive (it had my os on it). I love my samsung 840 256gig and am debating getting a second. 

I really like the Samsung drives. You won't see as big of a difference as someone like me who came from an HDD to an SSD, but jumping from SATA II to SATA III will be nice. Also the capacity will be much higher, so you won't have to be so selective about what game(s) you have on it.

I wouldn't touch the Samsung EVO SSD as they are using TLC instead of MLC which has much lower lifespan.
 
Samsung 850 Pro while good is very expensive if you consider the price/gigabyte you gonna get.
 
Drives like Crucial MX100, Sandisk UltraPlus, Seagate 600 are really good drives especially the price/gigabyte while not sacrificing any noticeable performance.

FattysGoneWildI currently have a Intel 320 160gb Sata II ssd. Thinking about grabbing a new Samsung 850 Pro 256gb ssd ...  I also seen a Intel 730 240gb ssd for a good price

Both of these drives are excellent.  The Intel one is based off their data-centre controller, so has very good IO consistency (IIRC at the expense of some peak write performance).  The Samsung 850 Pro also gets excellent reviews.  Both have very good write endurance ratings (70GB/day for 5 years for the Intel [about 130TB], and 150TB for the Samsung), and good warranties (5 years for the Intel, 10 years for the Samsung).  It's kind-of a "you can't go wrong" choice.
 
As to whether it's worth it... I suppose the question is are you noticing your current drive is too small, or slow?  Or are you hammering it with lots of writes? 
 
As others have mentioned, there are better-value drives out there (e.g. Crucial MX100).

I have the Samsung 830 Series in my HP Envy 17.  The main drive in my X99 system is a Samsung 840 Pro 512 GB.  I cannot say enough good things about Samsung.  The D drive in my laptop is a 300 GB Intel 320 Series...sata II.  The Samsungs are some of the fastest, most reliable you can get.  YAY on Samsung!!!  You'll love it.