Well, I wouldn't go that far. I just like the idea of them being the original design and prefer the bevel edge cabs. Sonic differences double blinded may be tough.
I use Small Advents in my garage, but have 3 sets of original Larges awaiting refoams. In fact, I'm considering bringing two sets to the Grumpfest (love that name!) so we can do the stacked Advents. I'm a homey for it, so going and getting them if anyone would want to hear would be no big deal. I'd probably run the LAs in a system, but with 20+ pairs of speakers here and a family, I gotta play favorites and so far my JBL 4311s win (but there are those La Scalas in the garage too!)
There's a ton of discussion on them over at AA on Vintage Asylum. "Bold Eagle" has really dug into these including reviews on recapping crossovers and internal wires. One thought is that the newer tweeters project better/wider and go down a bit lower I think, but some feel that the cutout in the grill contributes to the originals directionality.
For what it's worth, I almost always buy Advents