Deciding graduate school... easier way out or face the challenge?
I think having more research experience ... will help when it comes to applying for programs.


This statement answers your own question (in terms of what you believe). By choosing a new school you will inherently be exposed to more research methods and ways of working. While it won't be in your comfort zone and more difficult to find an adviser, you expand your horizons by meeting new people.


  Which decision will benefit me more down the road?


A diverse education is often seen as a huge plus to universities when choosing their PhD candidates; especially if they are at prestigious universities. It shows that you can adjust and adapt to new environments. That being said, maybe a professor at your current university has a great connection to the school where you may want to get your PhD and you wish to leverage that connection? There may be a few reasons to stay, but by not going you risk missing out on countless unknown opportunities.