So many good things done with this set.
28 total Gen 5 Pokemon. Some of these are including Pokemon we haven't seen since the BW era. Basculin, Archeops, and Carracosta come to mind of the ones we haven't seen (Leavanny/Terrakion have already been established). Stuff like Wynaut for the first time since, I think the HS era? Finneon/Lumineon, Elgyem/Beeheeyem, and I think a few others got their first cards since the XY era, and a lot of cool types for Pokemon, like Fighting Heracross and Steelix.
This is why I don't believe Pokemon is doing only gen 1 pandering. They're getting closer and closer to striking that balance with the last few sets. Although you have ultra rares with popular Pokemon, they're doing a lot of things like this that show they're acknowledging the other Pokemon out there.