I'm planning a big upgrade for a desktop PC which is 6 years old already.
The thing I've found it was more limited was in RAM quantity (only 2GB).
My most memory demanding tasks now require about 8GB of RAM (without the OS, programs, etc).
Since I want to be future-proof, I've decided to max out whatever is the maximum RAM in the new system (32GB)
I'm currently considering to buy an Asus Crosshair V Formula Z, and an AMD FX-8350 CPU.
Since both components support ECC RAM, and my budget seems to be enough to buy it, I'm considering that option.

But, is it really worth it?
How common are bit-flip errors in modern RAM?
Is the performance drop noticeable?

ECC RAM availability in my zone is pretty rare, but I've found this kit that may work:
KVR16E11K4/32 (4x8GB DDR3 ECC 1600Mhz CAS 11)

It isn't listed in the motherboard docs thought, so it's a bit risky. I haven't contacted Asus yet.