We had a furnace problem. The technician arrived on schedule, and promptly identified the problem (a cracked plastic cover allowing condensate water to leak). A different technician returned the next day and installed the replacement part. That time for each visit was approximately 20-25 minutes.
Both technicians were very professional & knowledgeable, friendly, and answered our questions.
My only suggestions are that (1) technicians should either wear clean booties or take off their shoes, especially when it's wet outside, and (2) the cost should be communicated in advance, and seemed a little high for the actual amount of time that was spent. I assume it was because that two visits were required. Several other service companies don't charge the minimum visit fee for a followup visit.