The bacon must be cooked correctly to really bring out the rest of the club. It can not remain too gummy by not rendering enough fat out, but it can not be so crisp that it shatters on the palate. That perfect bacon crisp is the hardest part to achieve, and the most important. Nothing ruins an awesome club like un-rendered bacon fat. A properly cured bacon is also necessary. One that is not overly salty and brings with it a slight sweetness really goes well with the other meats and fixings in the sandwich.
Well now I hope that I have instilled a little hunger in you to go out and experiment with this wonderful sandwich. Feel free to put up your favorite combination of club for others as well!