I guess, I will start with saying that air duct cleaning is almost never needed. It is not a scam, but it is certainly something that uneducated homeowners get suckered into. In regards to air flow, a well balanced HVAC system should be able to deliver more than enough air flow. If you are not getting good air flow, it's because your system may be out of balance. Additionally, regular cleaning/changing of the air filters will solve about 95% of your problem. Though you would be surprised how many people either a. don't have a filter or b. don't know about it and leave it there for 10+years. a washable one should be cleaned every 6 months(spring and fall) and a disposable one should be replaced every 3-4 months.
We installed a TRANE XL18 HVAC with a TRANE HV80 furnace 16 years ago and it still works great in Tucson, AZ. We inquired into a replacement for the future since the R-22 refrigerant will be off market at the end of this year. Our maintenance folks want to sell me a new system anyway (even though the TRANE works great). We are considering the BOSCH Inverter heat pump as a lower cost option down the road. Watch out for the tricky salesmen trying to sell beer at champagne prices though. Get estimates on whether you need to replace your current system and how much it could cost. And if they are factory certified.
"Customer service was great, and the price was in-line with other places, and fast service. We had a whole replacement of the outside and inside. I would have liked to see a better install for the furnace and new thermostat - the new thermostat should have gone where the old one was, and even tho the new furnace was a tight fit, they didn't offer to come back and repair the case molding, or give me a discount on the damage done, and I believe they should have put a disconnect box on the outside of the home, to make it easier for any future repairs needed. Other than that, am very happy with the cooling and heating!"