External GPU via Thunderbolt

Question

With the new Mac Mini refresh, any hope of a new discrete GPU inside has been completely killed.  That said, I need a new PC still, and I'm willing to get creative in order to find a Mac that suits my needs inside my budget (under $1k, gaming capable).  While initially disappointed, I did have a Eureka moment when I saw a Thunderbolt PCIe enclosure for external cards, but I have a question to ask first.
To those who have tried it, what success did you have with External GPUs over Thunderbolt?  I'm well aware of the limitations of the Thunderbolt spec, in that it's essentially a PCIe 2.0 4x slot, but I also know that many higher end desktop GPUs don't even saturate an 8x slot, and that the lower end ones use even less bandwidth, despite the slot length.  My idea was to grab a Thunderbolt PCIe enclosure, like the OWC HELIOS, and jam a GeForce 650 inside for gaming purposes.  Allegedly, it works fine under Windows with some tweaking and software hacks, but I want to get confirmation before I run out and drop the coin for such a setup.  I'm absolutely dying to switch to Mac here, and I'm willing to Frankenstein my way into a good setup if need be, I just want input from those who have tried or succeeded with it first.
Thanks!

Answer 1

For what it's worth to other people searching I did find this article on Tom's Hardware about the Echo Express Pro, which showed me two things:
The solution works on Windows, since it sees Thunderbolt as a PCI Express slot.
It likely won't work under OS X, since Apple doesn't support it, nor do vendors.
The latter point isn't necessarily a bad thing, it's just a symptom of a bad round of hardware design by Apple on the Mac Mini, combined with their desire to keep the platform as stable as possible by limiting hardware driver support to 3rd party peripherals and whatever hardware they shove into the Mac itself.  I can understand where Apple is coming from, even if I disapprove of it in this specific case.  That said, while the current Mac Mini doesn't meet my needs on its own, Thunderbolt makes it possible to meet my needs for gaming, so long as I don't mind booting into Windows 7 to accomplish it.  The major downside to all this is cost: with a Thunderbolt PCIe enclosure running $380 to $1000, and a low power gaming GPU like the GeForce 650 going for $120, you're looking at $500 or so alone just to get into the game, not including the cost of the Mac Mini itself which, if you're a gamer anyhow, is at least $1200 with that spiffy Fusion Drive and an AppleCare warranty!
Still, it's an option. Just not a very reasonable one.  As much as I'm absolutely dying to switch, I guess I'll try holding out another year to see if the next refresh fixes the Mini and brings back discrete graphics.  This price of entry is just way too steep.