Yes, lots of experience and it is very delicious -- especially if you pick it while it's still cool out. You can eat all parts of brassicas -- flowers, seed pods, bolted leaves and all.

Well, it certainly would not be poisonous. The easiest way to know if it still tastes good is to pick off a leaf and chew it. If you do not like it, spit it back into the bed and pull the plant for the compost. If you do like, pull the plant for the kitchen.

okay, but brassicas also get sweeter when cooked, so cooking some might be the very best test.