I guess everyone has their favorite widget, but I like my L/N rabbet block plane for trimming cheeks. I don't see the end of the tenon in the finished product, so I don't much care about blowing out the end grain. I also machine cut my tenon cheeks before tuning them with hand tools, so I don't have the parallel loss issues people have with hand cut cheeks. I trim my shoulders with a sharp chisel. It's the only way I know of to completely avoid blowing out the end grain, and it also lets me undercut the inside edges for a tighter fit in the visible part of the joint.

shoulder planes are nice, but to be honest, I don't get a lot of use out of them.