Just ordered my 5k iMac...

[fathergll]

Faster - Yes
Cooler - Maybe...I put one of those blade SSDs in a external drive and erased it. Got pretty hot.
Noisy - I hear no noise from my fusion drive and if there is noise its inconsequential
Vibrations - I dont hung my iMac and I don't feel any vibration on my desktop so I think this is not a valid concern
Mechanical - Yes much less reliable but the SSDs can and do fail with the same disastrous results. A backup solves this.

So from my perspective the only reason for the SSD is the "Need for Speed".

Agreed on the above. I never heard noise from the fusion drive.

I look at the fusion drive as literally having two drives so while there is a higher chance of failure you still can decouple the drives and use the working SSD in case of a failure(obviously the OS is toast and will need to be reinstalled).

My rMBP had an SSD and I did like how fast it booted. The iMac fusion boot is not bad. I could get it back it I unfuse the internal drives. For me the bottom line is Apples asking price for SSD is just ridiculous. My 3.5/8GB/1TB Fusion 5K only cost $1800. That's the sweet spot as pricing goes. I am not going to add $750 to pay full retail just to get that 512GB SSD and loose 50% of my storage.

I've had a base model since Nov last year and completely agree. Probably the biggest reason to get the fusion drive is the fact that they have the best deals on them. Even a month after they were released last year you could save $500 compared to a BTO model from Apple. Now the deals of $1800 are an incredibly good buy.

Obviously the fusion won't work for everyone especially if you are using it for work in terms of needing max speed when editing 4k features.

 

[MiniMi]

Congrats, have had a 5k with the 3tb fusion drive (since they came out) and love it. Absolutely no problems with it. I game as well as all the usual stuff. Enjoy