I am doing a rehab right now...I have the same decision to make this is what made it a no brainer...
Installing a higher efficiency unit (you can get money back for going high efficiency/green our local utility provides) I think it is $2500 now....This is a nice chunk of money to save. We have several other properties and just knowing our tenants wont be using window units let me not worry about leaks from them destroying the sills and floor.... yes this has happened before to me...My gut tells me we can charge a bit more for central air in the property.
I had to install all new ductwork and registers etc. But remember there are additional costs associated with the conversion.... you will have to remove all the radiators..mine are large cast iron lots of labor. If your going to pay for them to be removed don’t just throw them out you can sell them.... or recycle them get some money back.
If you have any questions feel free to message me when you have time.
Disclosure I am in the HVAC trade..
Thanks