There's naturally a lot of anxiety and disappointment from many here about the new 2013 Mac Pro and particularly in the lack of internal expansion. I even share some of it, having been an active tweaker of my own 2009 Mac Pro. However, I think people will get over the lack of expansion (some taking longer than others). I mean at some point sound cards went exclusively external and no one complained about cables or boxes. The same will happen for media storage arrays too - in fact many of us already use a NAS or external storage. I think the only legitimate complaint about upgradability lies with the GPUs and I understand the complaints from those that need the latest and greatest GPU every year, but that's not me. Anyway, the point of this thread, is not to justify or complain about the lack of internal expansion in the 2013 Mac Pro... rather, it's to share my reasoning as to why this is an optimal buying cycle. They key building blocks of any computer are the CPU, GPU, Memory, Storage, and display. And every year, there are incremental improvements in these building blocks, and their interconnects (PCIe bus, memory architecture, SATA, etc.). Some of these incremental updates Apple is a key force behind, others they simply adopt, and some they ignore completely. Once every 3-5 years, both at Apple, and in the PC world in general, there's an alignment of the planets where a bunch of new technology comes together that really creates a new generation of computer. For me, the last time this happened was around 2009 when Intel launched their Nehalem platform which was a truly new computing architecture with brand new memory architecture and multi-core CPUs. At the same time, SSDs were just coming to market along with LED displays (BTW, the display is perhaps the most important aspect of any computer to me). Since then there's been a series of incremental improvements in CPUs, GPUs, Memory, SSDs and displays. For example, since I purchased my Mac Pro in 2009, SSD storage has continued to get more affordable and performance has improved, SATA3 is now the standard for storage, USB 3 has become mainstream, and TB has emerged. When you look at the upgrades I've made to my 2009 Mac Pro, not surprisingly, it's been more SSD storage (with a SATA3 card), upgraded RAM, and added a USB 3 card. In my mind, the 2013 Mac Pro, is another alignment of the planets where a bunch of new technology is coming together at once... A new generation of multi-core CPUs, Thunderbolt 2, PCIe based storage, 4K displays, and dual GPUs in an environment where GPU compute seems to be on the verge of taking off. There is no doubt in my mind, that this is the right year to buy a completely new computer. Sure, I'll need a USB 3 enclosure for my spinning HDs but those are a dime a dozen these days. And what about all those incremental upgrades that are bound to happen over the next few years? I'm sure I'll feel the emotional draw to the latest PCIe SSDs that do 2GB/s, TB 3 or 4, the next two generations of GPUs, etc. These are all going to be upgrades I wish I had, but ones I certainly won't need. The technology in the new Mac Pro is bleeding edge enough that it will be at least a few years before anything comes along that I absolutely must have that can't be added via TB2... and at that point, the planets will probably start to align again around the next buying cycle. So I think if you've got a 2010 Mac Pro or older, this is the year to buy. Buy as much SSD in the new Mac Pro as you can afford, whatever RAM and GPU power you need, and then get a USB 3 enclosure for your drives and don't look back.