rockhead

+1 for the Curious tail and the Regen. It's really that good.

Of all the remasters so far, Led Zeppelin II sounds the best....the drums in particular shine.

Absolutely correct! It's like they sent John Paul Jones on a vacation. I also purchased the hi-rez files from HD Tracks.

I'm running Audirvana Plus on a mid-2008 MacBook Pro running Yosemite and using "Screens" to control the MacBook Pro from my iPad and iPhone. Link below....works like a champ over my local network. https://itunes.apple.com/us/app/screens-vnc-access-your-computer/id655890150?mt=8

Here's an alternative solution for the HD that will work with both USB 3.0 and Firewire. It will give you the flexiability for later MacMini upgrade. I would also recommend the Audioquest firewire cables for the HD, they make a big difference. Hard Drive: http://www.amazon.com/G-Technology-G-DRIVE-Professional-Strength-External-0G02537/dp/B009AP6X0C/ref=sr_1_3?ie=UTF8&qid=1422461389&sr=8-3&keywords=gtech+firewire

I've gotten 24/48 .aiff files to play from both my iPad and iPhone

Well maybe yes or no. I tried my DragonFly 1.2 with the camera connection cable from my iPad Air running IOS 8 and there isn't enough power for the iPad to run the DragonFly. Perhaps a powered USB s/pdif converter or powered DAC would indeed work. The next challenge being getting Hi-Rez files transferred to your iPad ;-)