I started off leveling SAM first in Stormblood and just recently got back to my SMN a couple days ago. It felt clunky as hell at first, but once I realized what I need to focus on in terms of timing the DWTs and Bahamut phase, it feels a lot smoother. There's also a LOT of room to adjust your rotation based on how a fight flows. Overall, it looks like SMN is now even more of a burst DPS than ever before.