Lane: Glad you are finding XRG useful. :-)

I did look into the option of upgrading my current Mac Pro. There is a lot of documentation online about how to replace the CPUs, which seems pretty straightforward (though easier with the 2010 model or later). The problem is that even older Xeon CPUs on eBay are pretty expensive. Once you replace the CPUs with high end units, buy a modern GPU, and get a bigger SSD in there, you're up to around $2k in costs. And you're still using a computer where most of the components have 5+ years of wear on them (I run my Mac Pro 24/7 too). At that price point, a new iMac would probably be the best option.

I decided it wouldn't be worth it to go that route, but I can understand it might make sense for a lot of other current Mac Pro users depending on where you are starting from and how much performance you are looking for.

After reviewing all the options out there, a couple of weeks ago I ended up ordering a new Mac pro with 6 core CPU, 16GB of RAM, 512GB SSD, and D300 GPUs. For storage, I picked up a diskless Pegasus2 R4 and I'm planning to put 3TB drives in that and run it in a RAID 5. I think this setup should last the next 5 years for my use. We shall see. Once the new system arrives, I'll be selling my 2009 model. That should definitely cover a big chunk of the expense of the new one as well.