The "more fun then most" comment applies to pretty much any of the Combat Arms trades. The PT is very demanding and there are a great number of chanllenges to get through; more so then in say an airforce or navy trade training. You will definitely learn a wide number of new skills and be challenged like you've never been before. The result is that once you've overcome these challenges you will feel as though there is nothing you can't do.
As for Inf vs. Combat Eng. both are great jobs, but equally different. The main difference that I would suggest between Inf and Combat Eng. would be that Combat Eng is a bit more demanding academically. It's not to say that there isn't a lot to know as an infanteer, it's just that I think the EOD component of the Eng.'s is demanding.
Instead of talking to recruiting, see if you can get in touch with people who are actually in the jobs right now. Better still, try and find some guys who are still fairly new to the jobs so you can gauge more accurately what their likes and dislikes are, and how those suit what you think.
