Big or little.You can get bad work out of either.Look
for a professional attitude in the sales person and
without being rude watch the unit go in if there in and
out slam bam.If your not sure after the job is over
hire a buliding inspector to drop buy just to take a
peak.Personaly little shops can give good work but are
financialy limited on the skill of help they can provide.
Look at this way if you get burnt at least you tride.We
guarantee no more than 2 degrees temp difference in any
room in the house.If you realy want to weed out the
hacks just say no flex duct(it will cost more)Flex is
a hacks secret weapon for speed. good luck