First off, to all the contractors/installers that have posted their great work in the "Wall of Pride" section, thankyou. Its good to see people take pride in their work, specially after working in a supply house and seeing what materials so many local contractors use.

I know it varies from area to area but, one of the biggest things I see from the other side of the counter is, contractors in this area use ALOT of flex, and very little sheetmetal duct work. At most, they tend to do do takeoffs with round pipe and then flex it the rest of the way out, leaving me seeing visions of the "flex octopus"( featured in the wall of SHAME), OR they use alot of ductboard trunklines ( this observation is based on what I see purchased from us ).
Another observation is, you can tell which of the contractors do mainly installs and few service calls, vs having combo teams or seperate install/service depts.
The guys that do mainly installs/roughins and startups, usually end up calling us in the supply house when they have technical questions that go beyond their very limited knowledge.
It also appears very few know how, or actually do a Load Calculation, meaning they base their equip sizing off of rule of thumb/sq footage. Last week alone, four of the larger contractors in the area were in the office at different times asking their "outside sales person" to help them figure load calcs that any decent Calc program should be able to do.
The last observation I'll comment on for now is about efficency ratings. Most new const systems are builder grade 10 seer, with a occasional 12 seer. Heat pumps with backup electric heat or gas seem to dominate( due to our milder winters ). One contractor yesterday, installed their 1st 90+ furnace and was lost when it came to venting it. Very few use or have tried to use anything above a 10 seer HP or condensor, which I find ODD considering AC is used for longer periods of time in this area.
Thats about all, sorry for the long post. Just some things I've noticed while being on the other side of the counter..