Looks like these are exactly the same product. I could be wrong, though. From the appearance of the Gravel Vac, and from what I know of my python, these two essentially perform the same function. I like the Python, and python was there first. Looks like "Lee" has managed to skirt patent laws to produce this other similar product.
If you're gonna get the python, get it from bigalsonline.com. They sell the 50-foot for $39 US. Great price!
(In case you haven't noticed, I'm a big fan of BigAls!)