Your block is beautifully done!
To answer your question, I always like to make a prototype block just to make sure there are no errors in the pattern...at least before I cut all the pieces and find out they had me cut a piece 1/4" too small. It also gives me a chance to see if I have any special problems with the block that I need to work out...figure out which way to press the seams if they don't tell me, etc.