I have read about Invasion being a popular set. Running through Mirage and Visions I have seen some fun cards, but not as many as I wanted. Now I can add Vintage Masters and Invasion Block into the mix and use that selection as my "learner" Legacy selection. I can spice up the decks as I please, of course, since the objective is to learn old cards, but while having fun. Concentrating on, say, phasing cards, has been 'un-fun.'
Talk about a change in power level down to Standard sets, Frenzied Tilling is a Rare in Gatecrash, here it is a Common!