I predict that rather than howling you will be purring. Meanwhile that mini will be quietly outperforming everything you ever had while running Yosemite, El Capitan, and future OS X versions without breaking a sweat.
^^This person. Is so right. Thank you!
YIPPEE SKIPPY!! My new mini, now equipped with a 1TB SSD, is home from the shop. I just finished getting it set up and started. After getting my document files copied onto it - and starting the copy of 292GB of photo files which is about half my photo library - I held my breath and opened Lightroom. KAZAM!! Not a beach ball in sight.
With the original HDD, it took Lightroom 45 seconds (!) to open. By comparison, on my 2013 MacBook Air (1.4GHz i5, 4GB RAM, 256GB SSD), it took 7 seconds.
Just now on the same mini, but now with a 1TB SSD? FIVE seconds.
I was going to wait until I'd spent more time using this mini with the new SSD, before posting the outcome of the switch from the old HDD. So I'd seem, you know, more mature and responsible and all that. To hell with that.

They can make me grow old, but they can't make me grow up. This mini is flying fast!! I'm happy dancing!




Bottom line, after the shop gave me credit for the trade-in of my 2008 iMac, is that this mini + the 1TB SSD upgrade cost about $1100 + tax. I also bought a new Magic Trackpad (love it), and I'm getting a thunderbolt to firewire adapter so I can use the same sturdy external drive for Time Machine as I was using with the iMac.
And though the repair shop gave me $25 less for the iMac than the quote I got from gazelle.com, it was worth it to not have to pack up that beast securely for shipping to gazelle and take the risk of damage in transit. I know, gazelle pays the FedEx shipping fee, and I've sold things to them before, but never anything as awkwardly big and heavy as that iMac. I
loved it for most of the time I had it but I'm not sad that it's gone to make room for my new stuff.
