If I run Vanitygen to look for a unique address and I hit 50% CDF during the calculations, does this mean I have tried 1/2 of the possible hash combinations for that unique address? So, at most I will spend an equal amount of time hashing the rest of the possible combinations before finding a solution, assuming the solution is the very last hash I try.

Am I also correct in my understanding that BTC mining CDF works a little different because the block we are all trying to solve changes every 10 minutes? So if I am solo mining and hit 50% CDF, I am not guaranteed to solve a block in another increment of time equal to the first 50%. In fact I may never solve a block in which case my CDF gets closer and closer to 100% but never quite reaches it.

In the first case CDF seems like a linear function and in the second case CDF seems very non-linear.

I tried searching for the answer without much luck.