I much prefer a sausage & egg biscuit from Hardee's but there are none locally so on the rare occasions when I'm out in the morning I'll settle for a sausage & egg croissant from BK.
If memory serves McD's hasn't had good luck developing new sandwiches; They "appropriated" the Big Mac from a smaller chain and as pointed out above egg muffins had been around for a long time.

__________________
No matter how strong, or brave, or pure of heart you may be; sometimes the dragon wins!