I have lived in Arizona for 30 years. Tucson used to be the closest city to where we lived and so we went there for shopping, doctor visits, etc. We recently visited and it has grown a lot although it is still nowhere as big as metro Phoenix. There is a lot to do in Tucson and surrounding areas. I'd totally give it a thumbs up for 8 months out of the year...
The only downfall is the incredibly hot summers so I'd go to
National and Local Weather Forecast, Radar, Map and Report and do a lookup for Tucson (c before s in Tucson) and look at the last 12 months or more of their weather. It is quite different from Massachusetts although every building has A/C and there are plenty of indoor activities for the hot months. The winter is mild and would definitely be the tradeoff for the hot summers. They actually got an inch of snow this past winter which was a first for them in many, many years! No snow probably sounds REALLY great to you!
Can you go visit and check it out for a week or so before deciding?

If so, I'd visit in June (dry) or July (humid -- monsoons) as these are generally the hottest months and would give you a true feeling for the climate.
Good luck with your decision... that's a big one!
If you have any specific questions, please let me know.