iMac upgrade. SSD or Fusion drive?

[Tyranor]

Greeting everyone,

I need a bit of advice.

I'm currently running PT11HD (standalone software) on late 2012 21,5" iMac with 16gb of RAM, 512Mb of video, 1Tb fusion drive and 3.1Ghz i7. OSX Yosemite.

I do audio post production and the current machine works fine but I'm getting busier and want to upgrade it to more powerful one + 27" screen.

I cannot buy current iMac because I then have to upgrade to PT12 and I'm not ready to do so.

I looked at the options and there is two available.

1) iMac 27" late 2013
3.5GHz quad-core Intel Core i7 (Turbo Boost up to 3.9GHz).
32GB (four 8GB) of 1600MHz DDR3 memory;
512GB PCIe SSD
NVIDIA GeForce GTX 780M graphics processor with 4GB of GDDR5 memory

2)iMac 27" late 2013
iMac (27-inch, Late 2013) - Technical Specifications
3.5GHz quad-core Intel Core i7 (Turbo Boost up to 3.9GHz).
32GB (four 8GB) of 1600MHz DDR3 memory
3TB Fusion Drive

Both have Apple warranty till July 2017. The difference is $500 (1st option is more expensive)

1st option looks better but I never worked with pcie SSD. Are they preferable to fusion drive? Obviously they are faster but is there any Pro Tools related issues with them? Are they more or less reliable that fusion drives? Is Halswell i7 and ProTools work fine? Also, 1st option has twice as much video memory but I don't play any games :)

Any feedback will be much appreciated