In article .com,
says...

As for the seat, I've never known a bike seat to be "comfortable," so
anything the least bit ergonomic gets my attention.

You are falling for ad speak. You need to figure out what makes the saddle
uncomfortable for you, and then find a saddle that addreses that problem.
Sometimes, it is only a matter of properly adjusting the saddle you have
on the bike, not getting a new one.

Seriously, how do the specs look? I want my shifts to shift right
away,

Most modern shimano drivetrains shift really well, even the really cheap ones.

and I'm leery of the claiper brakes...but I'm only just
above-average when it comes to bike knowledge and know-how, so I was
hoping you could help.

There is nothing wrong with caliper brakes. What are you concerned with them?
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Alex