Personally for me, definitely. I'll have more anticipation as the series goes on since I know what happens, but the ending will have drastically lower impact.
Yup, I do this if I type in the name of a show into a search engine and the results are something like "[showname] [character] dies/death/twist/whatever". I try to convince myself that it's not true, because actually a lot of the time it does turn out to be untrue!