HVAC advice about evaporator coils.
I need feedback primarily from those of you working in the HVAC field. I'm about to replace a gas pack unit and in the course of my research am finding a lot of complaints about evaporator coils leaking. Several local HVAC contractors have confirmed what I've seen online as well : an industry wide problem with evaporator coils leaking coolant, primarily due to "Galvanic Corrosion" in copper tube & aluminum fin assemblies. And, as a result of this corrosion wherever the two dissimilar metals are joined, the need for costly repairs or in many cases complete replacement. I have read about the all - aluminum evaporator coils in T's "Spine Fin" design and the " Micro - Channel" units by Nord.( which only came out in 2010). Are these all - aluminum assemblies proving more durable in the field than their copper/aluminum counterparts? Or are they prone to leakage also and or to other repair or maintenance problems as well? And, is there another option I've not mentioned that addresses this? Please be as explicit and detailed as possible. I know many other homeowners are grappling with this as well and need your expert advice - like me - to make an informed decision. So, please help and thank you up front.