When we replaced ours, we got three bids and recommendations. That should be enough for you to listen and then trust your gut. We replaced our 1974 furnace/central AC with a high efficiency one, and it saved a lot of money in heating/cooling costs.
For our VT house here we are looking at a mini-split to replace electric baseboard and to add AC, but that is probably not what you're looking for, but there are new options out there that I didn't even know about a year or so ago.