Mini splits are superior in every way to forced air AC, IMO. Being in MA, I assume that you have radiator heat (hot water)? No way Id want to lose that... Mini splits do put out heat down to low temperatures, but they do so essentially by taking less and less energy from the environment, and more and more from supplemental heaters (as I understand it). I didnt opt for more heat capability, and ours will throw some down to 10-15F, below which it really doesnt do much (I believe the ones with supplemental heat are good to -4F or so). IMO it would be too expensive to do so anyway, compared to gas.
For AC they are awesome. Super-high efficiency that forced air can't beat, super quiet, no ducting losses, etc.
HVAC contractors are some of the biggest crooks around though. You can install ducting and forced air for the same, sometimes less than the splits... Though the split units are cheaper to buy... And only require a lineset to be run from point A to B. Their strawman excuse of that they dont know what theyll encounter when running the lines is garbage, as they typically get run on the exterior in line hide, or have very short runs through walls that require little more than a 3" hole.
The downside to doing too many rooms is that you either have to buy a multi-channel unit, or else you need more linear area along your house to put the condensers.