I've tried it, using recommended hardware.

You will spend more time supporting that machine than you now think.

if it's earning you money, spend money, not time?

It's absolutely worth it...and then some.

It does depend a lot on how savvy you are with tech and computers, admittedly. But DO NOT use EFIX. EFIX uses the same base software modifications that TonyMac does, but they put it in an easy-to-use USB dongle that plugs straight into your motherboard. There was a huge hullabaloo here a while back about them selling software that is already free.

That, and it's "proprietary", so you can't update your computer if EFIX doesn't put out an update. I did it with the TonyMac method and never looked back. When the OS comes out with a point update, hit the forums and look for the official TonyMac announcement in the blog about how to safely upgrade.

I built my computer using the then-new Sandy Bridge CPU. It was so new, I was one of the "pioneers" trying to figure out the workarounds to get it to work (I bought the chip the day it was released). It was Hell. But that's because nobody knew how to work it. Now, you can skip that, as people have done the legwork for you.

My suggestion? Use Custom Beast. You buy the hardware, tell them what you have, and they build you a custom installer for that hardware specifically. Or check the CustoMacs for directions on how to build a Mac-equivalent Hackintosh. Want a Mac Mini? They have it listed. And part-for-part, the price difference will astonish you. At the base level Mac Pro you may save only a couple hundred by building it yourself, but if you want a higher-end Mac Pro, the savings of building it yourself becoming exponential. I built a $3000 mac for $1200. I used the extra cash to buy 3 monitors and an awesome 6-screen-capable graphics card.

Two screens horizontal for the PT Mix Window, two screens vertical for the Timeline, and one monster screen for the video. Do that on a standard Mac Pro...

And you can overclock and watercool a Hackintosh, so you can have a blazing-fast CPU for the most demanding sessions, and your water cooling makes your tower so quiet, you can leave it in the same room that you edit in. Do that on a standard Mac Pro...

Is it a lot of time spent? Depends. Possibly. Will you enjoy every moment of the result? YES! I slaved over my Workstation for 3 weeks trying to work out on the bugs on the new SandyBridge processor. But if I'd started building this thing just today, there are so many tutorials on how to do it, it would have taken me a day.

If you'd like help, I'd love to give you any advice or pointers on this. I'm a huge Hackintosh proponent (obviously).

I never tried the hackintosh project, but in my opinion right now is the worst time to buy a new mac (i guess you're talking about the mac pro). Because the actual mac pro (i use it since 2 years for my pt hd3 system) is not new (and loud), and nobody knows if or when Apple will release new mac pro's.

I'm also really interested in the experiences of Pro Tools HD Hackintosh Users.

That's a lot of variables you would be playing with. You've got to get Mac OS and Protools running without any official support (which you pay for in the cost of the software). Probably the biggest issue is that if you do get it working with Protools 10, you never know what's going to happen at 11. You might get stuck until you can afford another computer.

I think this depends on whether you want this as a challenge or not. Weigh up the time and cost benefits.

I have created a working hackintosh and I briefly worked with it, but setting it up and getting it working cost me lots and lots of time. I mean days and days, with kernel panics, editing of configuration files, endless reading on forums and a lot of looking at my system while it was rebooting (granted, I didn't pick recommended hardware, just hardware that others have had success with).

And even then, it wasn't 100% stable, which means unexpected crashes and kernel panics every now and then. Plus every update of a driver, a program or the OS has the potential to make the system so unstable you'd have to reinstall everything.

This could be a challenge, and it could be fun. But if anything depends on your ability to actually be productive with that machine, I'd strongly recommend against it.

On the other hand, as pointed out by @Nils, this is the worst time to buy a new Mac Pro. The hardware is from mid-2010 but still with unchanged prices, and the future of the entire Mac Pro line is unsure. The best value for money might be a used, previous generation Mac Pro.