I use 6lb mono and get about 2' deeper than I do with 10lb mono due to smaller diameter, that ratio will vary some depending on how much line you have out. In other words, I can cover 13-16' with 3 rods on a side running 55-75' of line out on 6lb vs. 3 rods running 65-110' of line with 10lb. I spend a little less time reeling in line and letting it back out this way and get a little edge on turning radius with the shorter line lengths. I tried some 4lb this year and had a few breakoffs but the 6lb is doing great, BPS Excel mono. Also, I didn't notice much difference in the running depths b/w the 6lb and 4lb, if your braid is 6 or 4lb diameter it should be pretty comparable to my results. I haven't tried braid for cranks but I'm happy with the mono because I like the little stretch it gives you running at 2 mph, you get some forgiveness when a big catfish hits it (landed a couple around 10-12lbs this summer on 6lb) and it probably hooks up a little better on crappie for the same reason. I don't lose many baits with the light line but I'm not fishing around a lot of snags either, that would be a good reason to go with braid or heavier mono for sure.