Slower times, but better age group results?

Times are effected by course, weather, wind, terrain and the like. It is even hard to compare the same race from year to year as swims can be measured wrong both years add in wind, and the like. You can be slower but do better. Comparing paces from one race course to another is even more difficult as the courses aren't the same.

I think often folks focus in on paces instead of how they did overall which compares you to all others.

If I were you I'd be happy with podium finishes!

What's your next race. Sounds like I need to sign up. 

Your friend was right. Not much you can do about competition at small races though.

I want to race with you!  Just did a sprint (3rd in the series for this group), last year for I was 3rd in my AG.  This year, 9 minutes faster and I was 5th in my AG.  To me everyone is getting faster.

What I've noticed around here is the first major sprint of the season is brutally fast with all the fasties. Then 3 weeks later, the local large Oly has the same fasties as they are building for HIM and IM's.  So as the season wears on, a high % of the fasties are going longer which opens up the field for us short-coursers.

Also, the heat/humidity does slow people down around here as the summer wears on.  Don't worry though, come September/October, the temps will drop, the long races will be over and the fasties will return.

Just my observations though.

No, the fields are getting faster in all my races that I've done (or follow for friends).