My G5 coped fine for years. Solid machine all round.
It wasn't until I started to use large sample libraries that I needed something more powerful.
Allot of the libraries I use are very CPU intensive, and most importantly eat up RAM like it's nothing.
A single patch in Cinematic strings 2 for example, can eat up over 500mb's of RAM in a single patch.
on 2nd thought I do have a small complaint. I wish I had SSD instead of a mechanical hard drive cuz the hard drive is definitely my bottleneck for performance. but like everyone else here I need a large drive to store various production-related shit. SSD isn't big enough and get too expensive.
mac mini 2013 16gb 2.3 GHz i7 core. 1 TB hard drive. I TB back up time machine. only regret is not upgrading to ssd as it's fast but could be way faster. overall great portable studio solution that has the balls to run quite a bit at once.
2013 Macbook Pro, 16GB RAM, i5 dual core, with 1 500GB SSHD. The upgrade to SSHD made a huge difference to the overall performance of the machine and is a worthwhile expense in any music machine. I wish I'd done that before the RAM upgrade to be honest. I'd have gone fully solid state over hybrid if I'd had the money at the the as well. The read time to and from the HDD is mega fast.
Absolutely no issues with any of my ITB editing software, or use with Ableton running multiple synths and plugins in a live environment.
If you want to use SSD, the best thing to do in my opinion is just use it as a second drive.
Have your regular 7200 drive for the majority if your stuff, and then us a smaller SSD drive for heavier work.
My sample libraries or on my SSD for faster load times with more complicated sample scripting, and then everything else is on a 1tb 7200rpm drive.
i7 with a ssd from pc specialist, does the job very nicely, contemplating upgrading ram to 16gb at some point as when I'm using a lot of vsts like addictive drums, keys and any synths the 8gb can get a bit low!
I don't use one. I've an mpc1000 and a yamaha a3000 for sampling, an rm1x and the mpc for sequencing, and a virus and k4r for synths and pads. Add a few misc effects and an edrumkit for programming beats.