Are Maintenance Plans Worth it?

My Air Conditioning unit recently gave up. Yup, it flat lined completely to the point of no return. Here in Florida we use our AC pretty regularly, and can often use it year around (some of the perks of our state). The Air Conditioning expert in Brandon FL came out to assess the problem and although he wanted to provide us with solutions – there really was only one, buying a new unit. Once installed, our expert let us know we could get a maintenance plan where they would come out twice a year to inspect our unit and make sure its running well. They even let us know they could provide some cleaning to keep the unit running as efficiently as possible. I need to decide in the next few days if I’d like to take them up on this plan, but wanted to get any comments on maintenance plans you may have. I’m leaning towards this being a good investment considering the large bill I was footed with to replace the unit, but I just wanted to make sure!