i have lots of friends flying on q400, A320, several on B737 and one on B747.
they all agree that flying a turboprop is harder and more demanding job and it will make one a better pilot.
unfortunately today that is not something that is appreciated.
if you don't intend to stay within same company and get to jet by seniority grab jet time!
also having experience in two types increases your chances to get some job if your company decide that your services are no longer neaded.