There has been an industry move away from refrigerant 22 (R22) toward refrigerant 410A. Homeowners needing major repairs may be faced with the difficult choice of replacing vs repairing air conditioning systems, and the need to change refrigerants in the process. For a condensing unit changeout, you may have the choice between installing a “dry-charged” R22 condenser, and reusing the refrigerant that was in your old system, vs replacing the old condensing unit with an R410A unit, but then also needing to replace the old R22 evaporator with a R410A evaporator. This second choice will cost more money now, but will leave you with a currently-used Refrigerant in your air conditioning system.
Which choice? Basically the choice comes down to spending approximately 25% more now and having a modern refrigerant, or spending less now and running the risk that you will not need to buy more R22 refrigerant for your home A/C system.
There is no absolute answer. Look at the prices of each option, and if one is dramatically less, then choose that one. The fact is, that R22 will be around for a long time, and while it may cost more IF you ever need to buy it, the additional cost should be far less than replacing your evaporator now. On the other hand, if you are buying a complete new system, you will want to make sure you get one that uses R410A.