Is there anything more exciting in literature than starting a new series?
Yes, the old, familiar faithful are nice. I am very loyal to a few ladies in mystery and paranormal romance (JR Ward, Charlaine Harris, you know who you are). But sometimes when you read the third or fourth installment in a beloved series you get bored reading the same character or place description as its re-re-repeated for the reader who somehow forgot what the main character looks like.
Also, starting a series is all about optimism of where the series could go. However, midway through a series all the readers what to know is…”how will it end?” That’s alot pressure and usually no one is happy.
The best is starting a series by an author you have loved in the past and can trust to deliver again.
That said…I’m about to start The Beautiful Ashes by Jeaniene Frost.
Accidental Author 
I also think it helps if the author has a general idea of where the series needs to or can go at the beginning of the series–it doesn’t have to be cut in stone–that way the pressure is less and possibly less repetitive. But that’s just me.