Or how they reuse names like chiefs special and M&P.
Paul, do NOT even get me started on that!
If I had the chance to pick up a "new" used 520 at an attractive price, I'd take it. The Hi-Viz sights, while certainly not "classic" looking, are damn effective, quick to align, and easy on the eyes. I have a set on a 1911 style gun, and everyone who plays with it is really impressed. Also, the titanium cylinder is a unique curiosity - the "rumor" was that's why they quit building it - it was too expensive. I'd also think the two-piece barrel system would give some impressive accuracy, like in the Dan Wessons.
19's are darn nice - I have two, and two 66's (the stainless variant). If you really get hooked, also try an older 4" 686 .357 - they are superb platforms - the full lug makes the perceived recoil of a .357 feel like a +p .38 out of a 19/66. Very impressive.
In all honesty, the 520/620 is more an un-lugged L frame than a "new" 19/66 - the size/weight are in the L frame class, not the K. It's only because it's unlugged, I think, that they call it the "new" 19/66. But hey, it's one of the very few post-2002 S&Ws with the ILS that I think is interesting enough to buy vs. pre-lock models. Let us know about it when you get it. I've heard very little user feedback on the 620, and none on the 520.