Getting some conflicting info on synthetic vs. sheep's wool. Please set me straight.

Lambs wool applicators will hold more finish than synthetic. You just need to know how to use it to spread the finish. Vacuum the applicator after it is fastened to the block before you use it the first time. Use the whole applicator surface to spread the finish evenly. Both will leave fine hairs the first time they are used.
I buy a whole sheepskin at a time. The neck area will be the best for a long lasting
applicator. You can use it for many finish coats if you store it correctly.