Spike, I thought maybe someone who has a B2150 would give you their opinion, but it depends on working conditions (how hard the ground is that you want to work, how heavy the brush is that you want to mow, etc.) and brand/model of implements (how heavy they are and whether they are too heavy for the 3-point). But basically, I'd say 4' brush hog, box blade, and tiller (I've never used the rakes and grader blades). You might be able to use 5' implements but would probably be pushing some limits pretty hard.
Bird