First of all, I'd like to thank everyone for their feedback and would
welcome any additional thoughts / opinions.
Regarding the ice, all I saw was a ball of it around some kind of hose
coming out of the compressor (?). Despite having an appointment for 2:30, he
didn't arrive here until 8:00 in the evening so it's possible that the ice
wasn't the real reason he wanted to wait until tomorrow. That's just as
well, though, since this has given me time to ask you folks for your
opinions, for which I'm grateful.
I should add that he didn't say that the coil definitely needed to be
replaced -- he simply listed that as one of the possibilites. He did mention
other possibilities such as the coil simply being dirty or having a minor
leak that could be fixed relatively cheaply. The part that concerned me was
his claim that coils normally only last 5-7 years, although the consensus
here seems to be that that's not true.