"The testing in this thread is actually making me a little more interested in using messing around with LAB color. Funny how things work sometimes."
Then I highly recommend Dan's Lab book, The Canyon Connundrum. As well as leading you through the ins and outs of Lab, it will also help you learn when Lab is appropriate and when it's not - and it's definitely not always a benefit. Knowing when makes you a better retoucher.
As far as Dan being totally down on hi-bit high gamut workflows, this is somewhat disengenuous. He's not and even advocates that for most processes it won't hurt. What he objects to, and this is my opinion, is that there is a certain constituent that claims it's always beneficial to work in 16 bit large gamut color spaces. You have to actually read his books to understand what his real opinion is and understand where his complaints are based. As far as large gamut, what's larger than Lab - well, mathematically maybe ProPhoto RGB, but not in the real world.
One of the cool things The Canyon Connundrum does is show you examples of how Lab interacts with different RGB workspaces with real world images and how you can take advantage of some of Photoshop's limitations when dealing with severely out of gamut colors
The most important thing to remember is that the typical single round trip into Lab and back does no real damage to the image, and if you're adept at your Lab adjustments, your image will benefit greatly.
On a practical note, I work on hundreds of stock images a year for various clients, getting paid to make some fairly mediocre iStock and Getty Images files look like I might have actually taken them. Every one of those stock images comes to me as an 8 bit (usually) sRGB number eight compressed jpeg, and I'd say that maybe 60 percent make the trip to Lab and either back to RGB or straight to CMYK from there. These are usually printed on high end presses at 175-200 line screen and they all look great, as do the Epson proofs I make prior to going to press. Yes, every once in a while, a blue sky falls apart, but it would have broken apart regardless. So, while it might not be advised, I'm living proof that you can move 8 bit jpegs to Lab and back if you need to.
Sometimes it's not that you can't get similar results in RGB, but it's the fact that I might have to plow through a hundred images in an afternoon and I'm after the fastest most efficient workflow possible. Not everyone "gets" Lab, but for those wiling to spend the time to really learn it, it can be one of the most powerful tools in your color correction/retouching toolkit.