I like spades because I perceive better contact area from a properly positioned and compressed spade and because spades are more readily available in high conductivity materials like copper, which is generally considered too soft for the structural demands of a banana connector where the wire hangs perpendicular to the connector. Banana connectors are often constructed from a copper alloy that is in the ballpark of 40-60 percent as conductive as basic copper.
Bigger isn’t always better. Cardas makes nice copper spades for soldering but one of my favorites is a fairly minimalist gold plate over high conductivity copper spade from Furutech (FP-203) that I crimp using a hydraulic die crimper that can almost achieve the level of connection that Cardas gets with their Forged Spade connections. I also will not argue with the benefit/performance of direct wire connections, assuming you have suitable binding posts, although I find that option better with solid core wire than with stranded wire.