I'm from Missoula, lived here most of my life. I don't know a lot about Bozeman, however I do have some family over there.
Missoula is getting bigger, so its going through growing pains. You'll especially see that in the traffic congestion around rush hour. One of the other things that's going on is this tug of war between people who want Missoula to remain a small, out of the way place, and those who welcome new growth and improvements. There's about a billion dollars worth of construction expected to occur in Missoula in the next few years. Some people like me embrace it, while others do nothing but whine and complain about those 'evil corporations' coming in and taking all of our money while ignoring the fact they're investing millions of dollars to improve the city. So yeah, there's a few cynical snobs with a big chip on their shoulders here, but the vast majority of Missoulians are friendly, helpful and welcoming.
Missoula is the banana belt of Montana because the mountains to the west shield us from much of the cold air that spills down out of Canada in the winter. Typically, snow doesn't start accumulating in Missoula until around Christmas. Once it does, we'll typically have a few inches on the ground at a time, but that's about it. In fact we've seen some winters that were bare and dry a significant amount of the time. So far, we've only had about three weeks of real, honest winter in Missoula this year, so sometimes it can be very mild here. Driving in the city in the winter really isn't a problem unless we get hit with an unusually potent storm, but that's maybe once or twice a season. But there's also winters when we do get hit harder than usual, so you really never know what to expect. If we do get a snow storm, the city usually plows the arterials and public transit routes first. Typically the sun will come out in the afternoon and melt any remaining snow. Sidestreets and residential streets are the last to get plowed, so you might have to deal with that. As someone who's always lived here, I really don't think our winters are that harsh. Spring usually arrives in March. We'll get some rain showers here and there. June is usually warm. The hot weather hits around the 4th of July. Expect 90-100 degree temperatures most of July and August. September cools to the 70-80 degree range. Fall is hit or miss. Sometimes it can be cooler than normal, while this last fall we enjoyed tee shirt weather right up to Thanksgiving. I think people get the impression we have two months of barely warm weather, but the other ten months are cool and/or snowing. That's not the case at all. Its about 6 months of warm to very hot weather, two months of actual winter conditions, and the rest is somewhere in between.
Take your pick. Missoula is a running, hiking and biking city. There's a big concrete "M" on Mt. Sentinel by the University. People hike up there daily. Its great exercise, and it affords a great view of the city 600 feet below. Missoula has 22 miles of interconnected trails and a plethora of parks. You can actually kayak right in downtown Missoula at Brennans Wave. People also float the river in droves. Missoula has several well known breweries and distilleries. If you like skiing and snowboarding, Montana Snowbowl is only 15 minutes north of the city. Missoula also has the Missoula Marathon, which was ranked the number one marathon in the nation a few years ago.
Missoula is a very dog friendly town. Sometimes I think every person in this city has a dog. The city has also set up places where dog's and their owners can gather, such as the Jacob's Island Bark Park by the University. If you're renting though, many property owners will require a pet deposit.
I don't think one can say that all of Missoula is laid back. Its a very diverse culture here, so yeah, you do have the laid back crowd, but you also have the goal oriented professionals as well. At the end of the day though, most Missoulians enjoy getting outside, hiking, relaxing, having a beer at a local brew pub, or enjoying an event at Caras Park downtown. One of Missoula's biggest assets is its outdoors and recreation, so its only natural for people to take advantage of that lifestyle when they have the opportunity to do so. I really don't think one city has an edge over the other when it comes to outdoor recreation. Missoula does have two big rivers running through the valley though.
You'll see lots of Subaru's and Audi all wheel drive cars here in Missoula, as well as larger SUV's. Missoula has a big Subaru dealership here. Personally, as stated above, unless you plan on hitting the mountains, a 4x4 may not even be necessary. My car is front wheel drive only and it does just fine for city driving and getting back and forth to work in the winter. An engine block heater might be a 'nice to have' for winter, unless you have a garage. Missoula's winters aren't that bad, however sometimes we get these artic blasts out of Canada that can drop the temperatures for a few days at a time, so that's when a block heater comes in handy.
I do want to correct a few misconceptions though. No, not everyone in Missoula smokes pot. Yes, its here just like any other city, but its not everywhere. Also, Missoula is not the Rape capital of the USA. Its tragic, however this is something that's occurring at university campuses all over the US, not just here. Missoula has received more notariety due to some high profile cases, and because of a recently published book.
The rental market in Missoula is tight, but its improving thanks to hundreds of new housing complexes. Keep in mind the market gets really tight when the college kids return to town mid-summer.
Missoula is also not lacking when it comes to arts and entertainment. We have lots of museums and art galleries, a symphony orchestra, theaters and more. We also get lots of amazing concerts here, such as The Rolling Stones, Paul McCartney, Nine Inch Nails, Foo Fighters and more.
Long post. Good luck in whichever city you decide to move to.