UMass Lowell is known for its engineering programs. I chose a different school for my education, but a number of my collegues are ULowell grads. I did reside in the city for several years and have both friends and business contacts in the city, so I'm there fairly often.
Lowell is a working class city divided into 5 disctict neighborhoods. The city's had its growing pains but has a reviltalized downtown and beautiful riverfront parks. Lots of restaurants featuring everything from high-end steakhouses to great diners (the Owl Diner is particularly well known) and Portugese mom-and-pop establishments.
The university has buildings on both sides of the river, but parking is tight so most students walk between the two campus locations.
I can't speak for their baseball team. Being from southern NH, now, I tend to root for Franklin Pierce, but I've heard Lowell has a good program.
As for things to do... the city has an active night life, a Red Sox minor league club (the Lowell Spinners), a minor league hockey team (the Loch Monsters), lots of concerts at the Tsongas arena, a cultural festival that takes over the downtown once a year, and an incledible regatta festival. There's crew and power boating on the river and a lot of folks walk, bike or rollerblade on the paths along its banks.
And if there's not enough to do in that list - Lowell is less than an hour from Boston and the NH and Maine coastlines. Its only 30 minutes to some of the smaller ski areas in Massachusetts and 90 minutes to some of the best skiing in New England (off I93 and I89 in NH). You can reach NH's lakes region and the White Mountains in a little over and hour or take a longer ride out to the Bershires in Western Mass.
As I said, I can't sell the college (except by reputation) because I didn't attend UMass Lowell, but I do know the city and its all about what you're looking for and what you like to do. If you like a mid-size working class city environment, it may be a good fit for you. I don't know what you like to do for fun, but your can find everything from rock concerts to rock climbing in the Lowell area.