Flemish are generally faster and stronger than EL - I make both for my bows - but less forgiving than the stock Excel string if the bow is dryfired. Suggest you use the stock string until you get a pattern down that prevents dryfire. 1) **** bow 2) engage safety 3) pick up bow and load.
Check out the Excal forum, Boo makes great strings and was very helpful getting me started.