Don't let these Fusion haters get to you. I have a Late 2013 iMac and the Fusion drive is still fast and going strong. I have had 0 problems with it for almost 6 years. I am going to be purchasing a 2019 iMac shortly and will be getting the 2TB Fusion Drive as well. From my own experience I can recommend it without hesitation. Good luck!
Thanks , i did decide to keep this configuration as opposed to returning it. if Apple stocked SSD Models in stores i might have gone ahead and exchanged it but i can't be without a computer for 2-3 weeks as thats the wait time for a built to order iMac model so im going to enjoy this 2TB of storage which is excellent. Great overall machine highly recommended. i just upgraded the RAM to 24GB as well. i could have upgraded to a total 40GB of RAM by getting 2 x 16GB sticks but that was twice the price of 2 x 8GB so i just did a total of 24GB by adding 2 x 8GB Sticks.