It all depends on your training goals. But my thoughts are different then debaser's. I definately believe focusing on seperate body parts makes a huge difference in gains and strength. Partly because Ive seen my training partner, who benches 400, and his arm strength, size and shape as far as anything else aside from flat bench, is poor in comparison to mine. He has alot more potential, but he only trains once to twice a week. No arms training, no shoulders, nothing else. Just chest and maybe back when he feels like it. Im sure hed be alot bigger and stronger if he started training more frequently and hitting everything fully. I can row 150lb dumbells for 20+ reps, 365 barbell as many times as I like and Im still not getting the bicep stimulation of 160lb preacher curls for reps. Theres just no comparison. My arms literally numb out many times during an arm workout, back barely pumps them. I definately believe you can get some overall growth from compound movements. The guy I train with went from 15.5 to 17.5 in the last 2 years doing mainly compound. But hes been plateaud for a long time. Im sure if he started hitting his arms hard theyd come up. JMO