SSD vs Fusion vs HD

I received a new Mac mini at work 3 weeks ago which has the Intel i7 processor and the 256GB SSD in it. I absolutely love it! I am using it with my old 30" Apple Cinema Display via an adaptor that was purchased with the Mac mini and it works great.

Since I have only used this Mac mini in one configuration, I cannot compare it with Mac minis that have a standard HD in it or one that has a Fusion drive. That being said, this Mac mini absolutely flies for disk access activities. I have a 2-year old MacBook Pro at home with Aperture in it 4GB RAM, and an i7 processor with the standard 500GB HD. I use my Mac mini purely for work, but as a test, I recently loaded 30 raw image files (averaging around 35MB each, IIRC) on it and those files loaded in little more than an eye blink whereas I had to wait about 10 minutes or so for them to load on my MBP at home. I installed Aperture on my Mac mini and the photos loaded in it near instantenously whereas at home, it waks a minute or two for each photo to load (same images).

I am an amateur photographer so I do a lot of photo work at home on my MBP. This Sunday morning, I am joining several other photographers to do a photo shoot at the Philadelphia Zoo, which is only a few miles from my office, so I am going to try editing those photos on my Mac mini. I expect to have at least 250 raw image files and editing that many photos at home on my MBP easily takes me an hour, but I expect to be able to edit them in significantly less time in my office on my Mac mini.

Even when you consider the speed of the Thunderbolt bus, SSD will always be faster than a spinning disk. You will not find many detailed stats on the parts used in any Mac...even though they're all off the shelf parts. Using your example of uploading a large file, the Fusion might give you the best of both worlds...fastest write times, and then tiering the storage off to cheaper spinning disk.

Are any portable Thunderbolt SSD drives available for sale anywhere now? If so, where? I have been keeping an eye out for them and even regular spinning portable HD Thunderbolt drives are a challenge to find, least of all at a reasonable price.