Many UMass upperclassmen make the move from dorm to apartment or house during their junior and senior years. I will be a junior next fall, so my friends and I decided we wanted to move on from dorm life and find a place of our own. After a very long process, we finally settled on a house to be shared by five girls, and I couldn't be more excited!
The most important piece of advice I can offer when considering an off-campus move is to start your search EARLY! My friends and I were late to the game, and it resulted in us having significantly fewer options trying to search in late November/December than September/October. Not to mention that all of the closest/cheapest options are the quickest to get taken off the market.
I also highly recommend taking advantage of UMass' off-campus housing search resources. Many of the local apartment buildings and realty companies post listings on the site that have been vetted by UMass, so you know that they are credible offerings. There is also an entire system to search for exactly what number of bedrooms and bathrooms that you and your group are looking for. If you aren't finding anything of interest there, the classic option of Zillow was very useful for my friends and I as well.
Try to set up as many showings as you can. Looking at pictures online can give you a good sense of a property, but it is a much different experience to physically see it for yourself. When setting up a showing with a realty company, they often take you on a tour of at least three to four houses/apartments so that you get to see more than just the original option you had contacted them about. We actually found our house through one of these secondary options they had picked out based on our group-size, so it worked out great!
Living off-campus is by no means necessary for a great experience at UMass, however I am looking forward to gaining the independence and responsibility that living on our own will bring.