So I'm finally having to decide if the Performance system is worth the $1780 extra. Both systems are 5 ton with furnace (but a larger furnace (110k) in Performance because the 90k unit isn't available to my preferred vendor).

My concerns:

1) Exterior unit protection/noise. Comfort units have wire guards, while Performance units have louvered covers. the wire guards flow better and are easier to clean...however, the Performance is quieter (compressor blanket and more enclosed) by about 4 db (marginally noticeable).

2) High/low protection switches are only in the Performance Series, but both are warranted for 10 years.

3) Furnace quality. The Performance furnace has a ECM motor, where the Comfort doesn't, and is a better unit.

4) Vendor has positive experiences with Comfort Series in this area, but also appreciates the better quality of the Performance Series.

Original thread here:

http://ths.gardenweb.com/discussions/4826994/a-c-replacement-quote-evaluation?n=14

Any closing thoughts from this knowledgeable community?